| SQL*Plus® User's Guide and Reference Release 10.1 Part Number B12170-01 |
|
|
View PDF |
| SQL*Plus® User's Guide and Reference Release 10.1 Part Number B12170-01 |
|
|
View PDF |
This chapter helps you learn to write and edit scripts containing SQL*Plus commands, SQL commands, and PL/SQL blocks. It covers the following topics:
Read this chapter while sitting at your computer and try out the examples shown. Before beginning, make sure you have access to the sample schema described in Chapter 1, " SQL*Plus Overview".
In the command-line and Windows GUI, the use of an external editor in combination with the @, @@ or START commands is an effective method of creating and executing generic scripts. You can write scripts which contain SQL*Plus, SQL and PL/SQL commands, which you can retrieve and edit. This is especially useful for storing complex commands or frequently used reports.
Your operating system may have one or more text editors that you can use to write scripts. You can run your operating system's default text editor without leaving SQL*Plus command-line or Windows GUI by entering the EDIT command.
You can use the SQL*Plus DEFINE command to define the variable, _EDITOR, to hold the name of your preferred text editor. For example, to define the editor used by EDIT to be vi, enter the following command:
DEFINE _EDITOR = vi
You can include an editor definition in your user or site profile so that it is always enabled when you start SQL*Plus. See "SQL*Plus and iSQL*Plus Configuration", and the DEFINE and EDIT commands in Chapter 13, "SQL*Plus Command Reference" for more information.
To create a script with a text editor, enter EDIT followed by the name of the file to edit or create, for example:
EDIT SALES
EDIT adds the filename extension .SQL to the name unless you specify the file extension. When you save the script with the text editor, it is saved back into the same file. EDIT lets you create or modify scripts.
You must include a semicolon at the end of each SQL command and a slash (/) on a line by itself after each PL/SQL block in the file. You can include multiple SQL commands and PL/SQL blocks in a script.
Example 6-1 Using a System Editor to Write a SQL Script
Suppose you have composed a query to display a list of salespeople and their commissions. You plan to run it once a month to keep track of how well each employee is doing.
To compose and save the query using your system editor, invoke your editor and create a file to hold your script:
EDIT SALES
Enter each of the following lines in your editor. Do not forget to include the semicolon at the end of the SQL statement:
COLUMN LAST_NAME HEADING 'LAST NAME'COLUMN SALARY HEADING 'MONTHLY SALARY' FORMAT $99,999COLUMN COMMISSION_PCT HEADING 'COMMISSION %' FORMAT 90.90SELECT LAST_NAME, SALARY, COMMISSION_PCTFROM EMP_DETAILS_VIEWWHERE JOB_ID='SA_MAN';
The format model for the column COMMISSION_PCT tells SQL*Plus to display an initial zero for decimal values, and a zero instead of a blank when the value of COMMISSION_PCT is zero for a given row. Format models and the COLUMN command are described in more detail in the COLUMN command and in the Oracle Database SQL Reference.
Now use your editor's save command to store your query in a file called SALES.SQL.
You can use a number of SQL*Plus commands to edit the SQL command or PL/SQL block currently stored in the buffer.
Table 6-1, "SQL*Plus Editing Commands" lists the SQL*Plus commands that allow you to examine or change the command in the buffer without re-entering the command.
Table 6-1 SQL*Plus Editing Commands
These are useful if you want to correct or modify a command you have entered.
The SQL buffer contains the last SQL or PL/SQL command. Any editing command other than LIST and DEL affects only a single line in the buffer. This line is called the current line. It is marked with an asterisk when you list the current command or block.
Example 6-2 Listing the Buffer Contents
Suppose you want to list the current command. Use the LIST command as shown. (If you have exited SQL*Plus or entered another SQL command or PL/SQL block since following the steps in Example 5-3, "Entering a SQL Command", perform the steps in that example again before continuing.)
LIST
SELECT EMPLOYEE_ID, LAST_NAME, JOB_ID, SALARY 2 FROM EMP_DETAILS_VIEW 3* WHERE SALARY>12000 |
Notice that the semicolon you entered at the end of the SELECT command is not listed. This semicolon is necessary to indicate the end of the command when you enter it, but it is not part of the SQL command and SQL*Plus does not store it in the SQL buffer.
The SQL*Plus CHANGE command enables you to edit the current line. Various actions determine which line is the current line:
When you LIST or RUN the command in the buffer, the last line of the command becomes the current line. (Note, that using the slash (/) command to run the command in the buffer does not affect the current line.)
If you get an error, the error line automatically becomes the current line.
Example 6-3 Making an Error in Command Entry
Suppose you try to select the JOB_ID column but mistakenly enter it as JO_ID. Enter the following command, purposely misspelling JOB_ID in the first line:
SELECT EMPLOYEE_ID, LAST_NAME, JO_ID, SALARYFROM EMP_DETAILS_VIEWWHERE JOB_ID='SA_MAN';
You see this message on your screen:
SELECT EMPLOYEE_ID, LAST_NAME, JO_ID, SALARY
*
ERROR at line 1:
ORA-00904: invalid column name
|
Examine the error message; it indicates an invalid column name in line 1 of the query. The asterisk shows the point of error—the mis-typed column JOB_ID.
Instead of re-entering the entire command, you can correct the mistake by editing the command in the buffer. The line containing the error is now the current line. Use the CHANGE command to correct the mistake. This command has three parts, separated by slashes or any other non-alphanumeric character:
the word CHANGE or the letter C
the sequence of characters you want to change
the replacement sequence of characters
The CHANGE command finds the first occurrence in the current line of the character sequence to be changed and changes it to the new sequence. You do not need to use the CHANGE command to re-enter an entire line.
Example 6-4 Correcting the Error
To change JO_ID to JOB_ID, change the line with the CHANGE command:
CHANGE /JO_ID/JOB_ID
The corrected line appears on your screen:
1* SELECT EMPLOYEE_ID, FIRST_NAME, JOB_ID, SALARY |
Now that you have corrected the error, you can use the RUN command to run the command again:
RUN
SQL*Plus correctly displays the query and its result:
1 SELECT EMPLOYEE_ID, LAST_NAME, JOB_ID, SALARY
2 FROM EMP_DETAILS_VIEW
3* WHERE JOB_ID='SA_MAN'
EMPLOYEE_ID LAST_NAME JOB_ID MONTHLY SALARY
----------- ------------------------- ---------- --------------
145 Russell SA_MAN $14,000
146 Partners SA_MAN $13,500
147 Errazuriz SA_MAN $12,000
148 Cambrault SA_MAN $11,000
149 Zlotkey SA_MAN $10,500
|
Note that the column SALARY retains the format you gave it in Example 5-4, "Entering a SQL*Plus Command (not in iSQL*Plus)". (If you have left SQL*Plus and started again since performing Example 5-4, "Entering a SQL*Plus Command (not in iSQL*Plus)" the column has reverted to its original format.)
See CHANGE for information about the significance of case in a CHANGE command and on using wildcards to specify blocks of text in a CHANGE command.
To add text to the end of a line in the buffer, use the APPEND command.
Use the LIST command (or the line number) to list the line you want to change.
Enter APPEND followed by the text you want to add. If the text you want to add begins with a blank, separate the word APPEND from the first character of the text by two blanks: one to separate APPEND from the text, and one to go into the buffer with the text.
Example 6-5 Appending Text to a Line
To append a space and the clause DESC to line 4 of the current query, first list line 4:
LIST 4
4* ORDER BY SALARY |
Next, enter the following command (be sure to type two spaces between APPEND and DESC):
APPEND DESC
4* ORDER BY SALARY DESC |
Type RUN to verify the query:
1 SELECT EMPLOYEE_ID, LAST_NAME, JOB_ID, SALARY
2 FROM EMP_DETAILS_VIEW
3 WHERE JOB_ID='SA_MAN'
4* ORDER BY SALARY DESC
EMPLOYEE_ID LAST_NAME JOB_ID MONTHLY SALARY
----------- ------------------------- ---------- --------------
145 Russell SA_MAN $14,000
146 Partners SA_MAN $13,500
147 Errazuriz SA_MAN $12,000
148 Cambrault SA_MAN $11,000
149 Zlotkey SA_MAN $10,500
|
To insert a new line after the current line, use the INPUT command.
To insert a line before line 1, enter a zero ("0") and follow the zero with text. SQL*Plus inserts the line at the beginning of the buffer and all lines are renumbered starting at 1.
0 SELECT EMPLOYEE_ID
Example 6-6 Adding a Line
Suppose you want to add a fourth line to the SQL command you modified in Example 6-4, "Correcting the Error". Since line 3 is already the current line, enter INPUT and press Return.
INPUT
SQL*Plus prompts you for the new line:
4 |
Enter the new line. Then press Return.
4 ORDER BY SALARY
SQL*Plus prompts you again for a new line:
5 |
Press Return again to indicate that you will not enter any more lines, and then use RUN to verify and re-run the query.
1 SELECT EMPLOYEE_ID, LAST_NAME, JOB_ID, SALARY
2 FROM EMP_DETAILS_VIEW
3 WHERE JOB_ID='SA_MAN'
4* ORDER BY SALARY
EMPLOYEE_ID LAST_NAME JOB_ID MONTHLY SALARY
----------- ------------------------- ---------- --------------
149 Zlotkey SA_MAN $10,500
148 Cambrault SA_MAN $11,000
147 Errazuriz SA_MAN $12,000
146 Partners SA_MAN $13,500
145 Russell SA_MAN $14,000
|
Use the DEL command to delete lines in the buffer. Enter DEL specifying the line numbers you want to delete.
Suppose you want to delete the current line to the last line inclusive. Use the DEL command as shown.
DEL * LAST
DEL makes the following line of the buffer (if any) the current line.
See DEL for more information.
You can enter comments in a script in three ways:
using the SQL*Plus REMARK command for single line comments.
using the SQL comment delimiters /*... */ for single or multi line comments.
using ANSI/ISO (American National Standards Institute/International Standards Organization) comments - - for single line comments.
Comments entered at the command-line are not stored in the SQL buffer.
Use the REMARK command on a line by itself in a script, followed by comments on the same line. To continue the comments on additional lines, enter additional REMARK commands. Do not place a REMARK command between different lines of a single SQL command.
REMARK Commission Report;REMARK to be run monthly.;COLUMN LAST_NAME HEADING 'LAST_NAME';COLUMN SALARY HEADING 'MONTHLY SALARY' FORMAT $99,999;COLUMN COMMISSION_PCT HEADING 'COMMISSION %' FORMAT 90.90;REMARK Includes only salesmen;SELECT LAST_NAME, SALARY, COMMISSION_PCTFROM EMP_DETAILS_VIEWWHERE JOB_ID='SA_MAN';
Enter the SQL comment delimiters, /*...*/, on separate lines in your script, on the same line as a SQL command, or on a line in a PL/SQL block.
You must enter a space after the slash-asterisk(/*) beginning a comment.
The comments can span multiple lines, but cannot be nested within one another:
/* Commission Report to be run monthly. */COLUMN LAST_NAME HEADING 'LAST_NAME';COLUMN SALARY HEADING 'MONTHLY SALARY' FORMAT $99,999;COLUMN COMMISSION_PCT HEADING 'COMMISSION %' FORMAT 90.90;REMARK Includes only salesmen;SELECT LAST_NAME, SALARY, COMMISSION_PCTFROM EMP_DETAILS_VIEW/* Include only salesmen.*/WHERE JOB_ID='SA_MAN';
You can use ANSI/ISO "- -" style comments within SQL statements, PL/SQL blocks, or SQL*Plus commands. Since there is no ending delimiter, the comment cannot span multiple lines.
For PL/SQL and SQL, enter the comment after a command on a line, or on a line by itself:
-- Commissions report to be run monthly DECLARE --block for reporting monthly sales
For SQL*Plus commands, you can only include "- -" style comments if they are on a line by themselves. For example, these comments are legal:
-- set maximum width for LONG to 777 SET LONG 777
This comment is illegal:
SET LONG 777 -- set maximum width for LONG to 777
If you enter the following SQL*Plus command, SQL*Plus interprets it as a comment and does not execute the command:
-- SET LONG 777
SQL*Plus does not have a SQL or PL/SQL command parser. It scans the first few keywords of each new statement to determine the command type, SQL, PL/SQL or SQL*Plus. Comments in some locations can prevent SQL*Plus from correctly identifying the command type, giving unexpected results. The following usage notes may help you to use SQL*Plus comments more effectively:
Do not put comments within the first few keywords of a statement. For example:
CREATE OR REPLACE 2 /* HELLO */ 3 PROCEDURE HELLO AS 4 BEGIN 5 DBMS_OUTPUT.PUT_LINE('HELLO'); 6 END; 7 /Warning: Procedure created with compilation errors.
The location of the comment prevents SQL*Plus from recognizing the command as a command. SQL*Plus submits the PL/SQL block to the server when it sees the slash "/" at the beginning of the comment, which it interprets as the "/" statement terminator. Move the comment to avoid this error. For example:
CREATE OR REPLACE PROCEDURE 2 /* HELLO */ 3 HELLO AS 4 BEGIN 5 DBMS_OUTPUT.PUT_LINE('HELLO'); 6 END; 7 /Procedure created.
Do not put comments after statement terminators (period, semicolon or slash). For example, if you enter:
SELECT 'Y' FROM DUAL; -- TESTING
You get the following error:
SELECT 'Y' FROM DUAL; -- TESTING
*
ERROR at line 1:
ORA-00911: invalid character
|
SQL*Plus expects no text after a statement terminator and is unable to process the command.
Do not put statement termination characters at the end of a comment line or after comments in a SQL statement or a PL/SQL block. For example, if you enter:
SELECT * -- COMMENT;
You get the following error:
-- COMMENT
*
ERROR at line 2:
ORA-00923: FROM keyword not found where expected
|
The semicolon is interpreted as a statement terminator and SQL*Plus submits the partially formed SQL command to the server for processing, resulting in an error.
Do not use ampersand characters '&' in comments in a SQL statement or PL/SQL block. For example, if you enter a script such as:
SELECT REGION_NAME, CITY/* THIS & THAT */FROM EMP_DETAILS_VIEWWHERE SALARY>12000;
SQL*Plus interprets text after the ampersand character "&" as a substitution variable and prompts for the value of the variable, &that:
Enter value for that: old 2: /* THIS & THAT */ new 2: /* THIS */ REGION_NAME CITY ------------------------- ------------------------------ Americas Seattle Americas Seattle Americas Seattle Europe Oxford Europe Oxford Americas Toronto 6 rows selected. |
You can SET DEFINE OFF to prevent scanning for the substitution character.
For more information on substitution and termination characters, see DEFINE, SQLTERMINATOR and SQLBLANKLINES in the SET command.
The START command retrieves a script and runs the commands it contains. Use START to run a script containing SQL commands, PL/SQL blocks, and SQL*Plus commands. You can have many commands in the file. Follow the START command with the name of the file:
START file_name
SQL*Plus assumes the file has a .SQL extension by default.
Example 6-7 Running a Script
To retrieve and run the command stored in SALES.SQL, enter
START SALES
SQL*Plus runs the commands in the file SALES and displays the results of the commands on your screen, formatting the query results according to the SQL*Plus commands in the file:
LAST NAME MONTHLY SALARY COMMISSION % ------------------------- -------------- ------------ Russell $14,000 0.40 Partners $13,500 0.30 Errazuriz $12,000 0.30 Cambrault $11,000 0.30 Zlotkey $10,500 0.20 |
You can also use the @ ("at" sign) command to run a script:
@SALES
The @ and @@ commands list and run the commands in the specified script in the same manner as START. SET ECHO affects the @ and @@ commands in the same way as it affects the START command.
To see the commands as SQL*Plus "enters" them, you can SET ECHO ON. The ECHO system variable controls the listing of the commands in scripts run with the START, @ and @@ commands. Setting the ECHO variable OFF suppresses the listing.
START, @ and @@ leave the last SQL command or PL/SQL block of the script in the buffer.
To run a script as you start SQL*Plus, use one of the following options:
Follow the SQLPLUS command with your username, a slash, your password, a space, @, and the name of the file:
SQLPLUS HR/your_password @SALES
SQL*Plus starts and runs the script.
Include your username, a slash (/), and your password as the first line of the file. Follow the SQLPLUS command with @ and the filename. SQL*Plus starts and runs the file. Please consider the security risks of exposing your password in the file before using this technique.
If you omit the slash (/) and password, SQL*Plus prompts for it.
To run a series of scripts in sequence, first create a script containing several START commands, each followed by the name of a script in the sequence. Then run the script containing the START commands. For example, you could include the following START commands in a script named SALESRPT:
START Q1SALES START Q2SALES START Q3SALES START Q4SALES START YRENDSLS
|
Note: The @@ command may be useful in this example. See the @@ (double "at" sign) command in Chapter 13, "SQL*Plus Command Reference" for more information. |
You can include an EXIT command in a script to return a value when the script finishes. See the EXIT command for more information.
You can include a WHENEVER SQLERROR command in a script to automatically exit SQL*Plus with a return code should your script generate a SQL error. Similarly, you can include a WHENEVER OSERROR command to automatically exit should an operating system error occur. In iSQL*Plus, the script is stopped and focus is returned to the Workspace. See the WHENEVER SQLERROR command, and the WHENEVER OSERROR command for more information.
You can define variables, called substitution variables, for repeated use in a single script by using the SQL*Plus DEFINE command. Note that you can also define substitution variables to use in titles and to save your keystrokes (by defining a long string as the value for a variable with a short name).
Example 6-8 Defining a Substitution Variable
To define a substitution variable L_NAME and give it the value "SMITH", enter the following command:
DEFINE L_NAME = SMITH
To confirm the variable definition, enter DEFINE followed by the variable name:
DEFINE L_NAME
DEFINE L_NAME = "SMITH" (CHAR) |
To list all substitution variable definitions, enter DEFINE by itself. Note that any substitution variable you define explicitly through DEFINE takes only CHAR values (that is, the value you assign to the variable is always treated as a CHAR datatype). You can define a substitution variable of datatype NUMBER implicitly through the ACCEPT command. You will learn more about the ACCEPT command later in this chapter.
To delete a substitution variable, use the SQL*Plus command UNDEFINE followed by the variable name.
There are eight variables containing SQL*Plus information that are defined during SQL*Plus installation. These variables can be redefined, referenced or removed the same as any other variable. They are always available from session to session unless you explicitly remove or redefine them.
Suppose you want to write a query like the one in SALES (see Example 6-1, "Using a System Editor to Write a SQL Script") to list the employees with various jobs, not just those whose job is SA_MAN. You could do that by editing a different value into the WHERE clause each time you run the command, but there is an easier way.
By using a substitution variable in place of the text, SA_MAN, in the WHERE clause, you can get the same results you would get if you had written the values into the command itself.
A substitution variable is preceded by one or two ampersands (&). When SQL*Plus encounters a substitution variable in a command, SQL*Plus executes the command as though it contained the value of the substitution variable, rather than the variable itself.
For example, if the variable SORTCOL has the value JOB_ID and the variable MYTABLE has the value EMP_DETAILS_VIEW, SQL*Plus executes the commands
SELECT &SORTCOL, SALARY FROM &MYTABLE WHERE SALARY>12000;
as if they were
SELECT JOB_ID, SALARY FROM EMP_DETAILS_VIEW WHERE SALARY>12000;
You can use substitution variables anywhere in SQL and SQL*Plus commands, except as the first word entered. When SQL*Plus encounters an undefined substitution variable in a command, SQL*Plus prompts you for the value.
You can enter any string at the prompt, even one containing blanks and punctuation. If the SQL command containing the reference should have quote marks around the variable and you do not include them there, the user must include the quotes when prompted.
SQL*Plus reads your response from the keyboard, even if you have redirected terminal input or output to a file. If a terminal is not available (if, for example, you run the script in batch mode), SQL*Plus uses the redirected file.
After you enter a value at the prompt, SQL*Plus lists the line containing the substitution variable twice: once before substituting the value you enter and once after substitution. You can suppress this listing by setting the SET command variable VERIFY to OFF.
Example 6-9 Using Substitution Variables
Create a script named STATS, to be used to calculate a subgroup statistic (the maximum value) on a numeric column:
SELECT &GROUP_COL, MAX(&NUMBER_COL) MAXIMUMFROM &TABLEGROUP BY &GROUP_COL. SAVE STATS
Created file STATS |
Now run the script STATS:
@STATS
And respond to the prompts for values as shown:
Enter value for group_col: JOB_ID old 1: SELECT &GROUP_COL, new 1: SELECT JOB_ID, Enter value for number_col: SALARY old 2: MAX(&NUMBER_COL) MAXIMUM new 2: MAX(SALARY) MAXIMUM Enter value for table: EMP_DETAILS_VIEW old 3: FROM &TABLE new 3: FROM EMP_DETAILS_VIEW Enter value for group_col: JOB_ID old 4: GROUP BY &GROUP_COL new 4: GROUP BY JOB_ID |
SQL*Plus displays the following output:
JOB_ID MAXIMUM ---------- ---------- AC_ACCOUNT 8300 AC_MGR 12000 AD_ASST 4400 AD_PRES 24000 AD_VP 17000 FI_ACCOUNT 9000 FI_MGR 12000 HR_REP 6500 IT_PROG 9000 MK_MAN 13000 MK_REP 6000 JOB_ID MAXIMUM ---------- ---------- PR_REP 10000 PU_CLERK 3100 PU_MAN 11000 SA_MAN 14000 SA_REP 11500 SH_CLERK 4200 ST_CLERK 3600 ST_MAN 8200 19 rows selected. |
If you wish to append characters immediately after a substitution variable, use a period to separate the variable from the character. For example:
SELECT SALARY FROM EMP_DETAILS_VIEW WHERE EMPLOYEE_ID='&X.5'; Enter value for X: 20
is interpreted as
SELECT SALARY FROM EMP_DETAILS_VIEW WHERE EMPLOYEE_ID='205';
Suppose you wanted to expand the file STATS to include the minimum, sum, and average of the "number" column. You may have noticed that SQL*Plus prompted you twice for the value of GROUP_COL and once for the value of NUMBER_COL in Example 6-9, "Using Substitution Variables", and that each GROUP_COL or NUMBER_COL had a single ampersand in front of it. If you were to add three more functions—using a single ampersand before each—to the script, SQL*Plus would prompt you a total of four times for the value of the number column.
You can avoid being re-prompted for the group and number columns by adding a second ampersand in front of each GROUP_COL and NUMBER_COL in STATS. SQL*Plus automatically DEFINEs any substitution variable preceded by two ampersands, but does not DEFINE those preceded by only one ampersand. When you have defined a variable, SQL*Plus will not prompt for its value in the current session.
Example 6-10 Using Double Ampersands
To expand the script STATS using double ampersands and then run the file, first suppress the display of each line before and after substitution:
SET VERIFY OFF
Now retrieve and edit STATS by entering the following commands:
GET STATS
SELECT &GROUP_COL, MAX(&NUMBER_COL) MAXIMUM FROM &TABLE GROUP BY &GROUP_COL |
2
2* MAX(&NUMBER_COL) MAXIMUM |
APPEND ,
2* MAX(&NUMBER_COL) MAXIMUM, |
CHANGE/&/&&
2* MAX(&&NUMBER_COL) MAXIMUM, |
I
3i |
MIN (&&NUMBER_COL) MINIMUM,
4i |
SUM(&&NUMBER_COL) TOTAL,
5i |
AVG(&&NUMBER_COL) AVERAGE
6i |
1
1* SELECT &GROUP_COL, |
CHANGE/&/&&
1* SELECT &&GROUP_COL, |
7
7* GROUP BY &GROUP_COL |
CHANGE/&/&&/
7* GROUP BY &&GROUP_COL |
SAVE STATS2
Created file STATS2 |
Finally, run the script STATS2 and respond to the prompts as follows:
START STATS2 Enter value for group_col: JOB_ID Enter value for number_col: SALARY Enter value for table: EMP_DETAILS_VIEW
SQL*Plus displays the following output:
JOB_ID MAXIMUM MINIMUM TOTAL AVERAGE ---------- ---------- ---------- ---------- ---------- AC_ACCOUNT 8300 8300 8300 8300 AC_MGR 12000 12000 12000 12000 AD_ASST 4400 4400 4400 4400 AD_PRES 24000 24000 24000 24000 AD_VP 17000 17000 34000 17000 FI_ACCOUNT 9000 6900 39600 7920 FI_MGR 12000 12000 12000 12000 HR_REP 6500 6500 6500 6500 IT_PROG 9000 4200 28800 5760 MK_MAN 13000 13000 13000 13000 MK_REP 6000 6000 6000 6000 JOB_ID MAXIMUM MINIMUM TOTAL AVERAGE ---------- ---------- ---------- ---------- ---------- PR_REP 10000 10000 10000 10000 PU_CLERK 3100 2500 13900 2780 PU_MAN 11000 11000 11000 11000 SA_MAN 14000 10500 61000 12200 SA_REP 11500 6100 250500 8350 SH_CLERK 4200 2500 64300 3215 ST_CLERK 3600 2100 55700 2785 ST_MAN 8200 5800 36400 7280 19 rows selected. |
Note that you were prompted for the values of NUMBER_COL and GROUP_COL only once. If you were to run STATS2 again during the current session, you would be prompted for TABLE (because its name has a single ampersand and the variable is therefore not DEFINEd) but not for GROUP_COL or NUMBER_COL (because their names have double ampersands and the variables are therefore DEFINEd).
Before continuing, set the system variable VERIFY back to ON:
SET VERIFY ON
You cannot use substitution variables in the buffer editing commands, APPEND, CHANGE, DEL, and INPUT, nor in other commands where substitution would be meaningless. The buffer editing commands, APPEND, CHANGE, and INPUT, treat text beginning with "&" or "&&" literally, like any other text string.
The following system variables, specified with the SQL*Plus SET command or in iSQL*Plus preferences, affect substitution variables:
See SET for more information about system variables.
System variables specified in the Preferences screens can affect iSQL*Plus behavior. The Substitution Variable Prefix, Display Substitution Variable, Substitution Variable Reference Terminator and Escape Character preferences affect variable substitution behavior.
iSQL*Plus will only prompt for input when scripts are invoked from the Workspace and output is being displayed in the browser (Below Input Area option). iSQL*Plus will not prompt for values when output is set to any of the other three options, or when invoked using the iSQL*Plus dynamic URL syntax.
iSQL*Plus prompts for each substitution variable as it encounters it by displaying a separate Input Required screen.
To synchronize variable substitution, set the Substitution Variable Prefix preference ON to set iSQL*Plus to always prompt for substitution variables before running any further scripts. Click the Execute button to execute the command.
Enter your script using '&' and '&&' as the prefix for variables. Click the Execute button to execute the script. iSQL*Plus prompts you for values for the substitution variables in your script. At the end of script execution, any double ampersand substitution variables in the script remain defined. This means that you are not prompted to enter values for these variables again, until they have been undefined, or you log out of iSQL*Plus. If this is not the behavior you want, then use single ampersand substitution variables in your script. You are prompted to substitute a value for each occurrence of a substitution variable created with a single ampersand. If you use DEFINE to define variable values in your script in this mode, the defined values override values entered in the Input Required screen.
Substitution variables can also be given values passed as parameters using the iSQL*Plus dynamic report URL syntax. These values can be sent to iSQL*Plus in a POST action from an HTML form you write. This enables you to write applications that gather all input in one form, and also to do field level validation in JavaScript.
When iSQL*Plus executes a script containing substitution variables, the Input Required screen is displayed for each substitution variable. For example, when you enter:
BREAK ON &&SORTCOL SELECT &SORTCOL, SALARY FROM &MYTABLE WHERE SALARY > 12000 ORDER BY &SORTCOL;
iSQL*Plus displays:
Enter a value for the sortcol variable. For example, enter LAST_NAME. Remember that when a substitution variable is defined with a single ampersand, you are prompted for its value at every occurrence. If you define the variable with a double ampersand, the value is defined for the session and you will only be prompted for it once.
When prompted, enter a value for the mytable variable. For example, enter EMP_DETAILS_VIEW.
You can bypass the prompts for values associated with substitution variables by passing values to parameters in a script through the START command.
You do this by placing an ampersand (&) followed by a numeral in the script in place of a substitution variable. Each time you run this script, START replaces each &1 in the file with the first value (called an argument) after START filename, then replaces each &2 with the second value, and so forth.
For example, you could include the following commands in a script called MYFILE:
SELECT * FROM EMP_DETAILS_VIEWWHERE JOB_ID='&1'AND SALARY='&2';
In the following START command, SQL*Plus would substitute PU_CLERK for &1 and 3100 for &2 in the script MYFILE:
START MYFILE PU_CLERK 3100
When you use arguments with the START command, SQL*Plus DEFINEs each parameter in the script with the value of the appropriate argument.
Example 6-11 Passing Parameters through START
To create a new script based on SALES that takes a parameter specifying the job to be displayed, enter
GET SALES
1 COLUMN LAST_NAME HEADING 'LAST NAME' 2 COLUMN SALARY HEADING 'MONTHLY SALARY' FORMAT $99,999 3 COLUMN COMMISSION_PCT HEADING 'COMMISSION %' FORMAT 90.90 4 SELECT LAST_NAME, SALARY, COMMISSION_PCT 5 FROM EMP_DETAILS_VIEW 6* WHERE JOB_ID='SA_MAN' |
6
6* WHERE JOB_ID='SA_MAN' |
CHANGE /SA_MAN/&1
6* WHERE JOB_ID='&1' |
SAVE ONEJOB
Created file ONEJOB |
Now run the command with the parameter SA_MAN:
START ONEJOB SA_MAN
SQL*Plus lists the line of the SQL command that contains the parameter, before and after replacing the parameter with its value, and then displays the output:
old 3: WHERE JOB_ID='&1' new 3: WHERE JOB_ID='SA_MAN' LAST NAME MONTHLY SALARY COMMISSION % ------------------------- -------------- ------------ Russell $14,000 0.40 Partners $13,500 0.30 Errazuriz $12,000 0.30 Cambrault $11,000 0.30 Zlotkey $10,500 0.20 |
You can use many parameters in a script. Within a script, you can refer to each parameter many times, and you can include the parameters in any order.
While you cannot use parameters when you run a command with RUN or slash (/), you could use substitution variables instead.
Before continuing, return the columns to their original heading by entering the following command:
CLEAR COLUMN
Three SQL*Plus commands—PROMPT, ACCEPT, and PAUSE—help you communicate with the end user. These commands enable you to send messages to the screen and receive input from the user, including a simple Return. You can also use PROMPT and ACCEPT to customize the prompts for values SQL*Plus automatically generates for substitution variables.
Through PROMPT and ACCEPT, you can send messages to the end user and receive values from end-user input. PROMPT displays a message you specify on-screen to give directions or information to the user. ACCEPT prompts the user for a value and stores it in the substitution variable you specify. Use PROMPT in conjunction with ACCEPT when a prompt spans more than one line.
Example 6-12 Prompting for and Accepting Input
To direct the user to supply a report title and to store the input in the variable MYTITLE for use in a subsequent query, first clear the buffer:
CLEAR BUFFER
Next, set up a script as shown and save this file as PROMPT1:
PROMPT Enter a title of up to 30 characters ACCEPT MYTITLE PROMPT 'Title: ' TTITLE LEFT MYTITLE SKIP 2 SELECT EMPLOYEE_ID, FIRST_NAME, LAST_NAME, SALARY FROM EMP_DETAILS_VIEW WHERE JOB_ID='SA_MAN' SAVE PROMPT1
Created file PROMPT1.sql |
The TTITLE command sets the top title for your report. See "Defining Page and Report Titles and Dimensions" for more information about the TTITILE command.
Finally, run the script, responding to the prompt for the title as shown:
START PROMPT1
Enter a title of up to 30 characters
Title: Department Report
Department ReportEMPLOYEE_ID FIRST_NAME LAST_NAME SALARY
----------- -------------------- ------------------------- ----------
145 John Russell 14000
146 Karen Partners 13500
147 Alberto Errazuriz 12000
148 Gerald Cambrault 11000
149 Eleni Zlotkey 10500
|
Before continuing, turn the TTITLE command off:
TTITLE OFF
If you want to customize the prompt for a substitution variable value, use PROMPT and ACCEPT in conjunction with the substitution variable, as shown in the following example.
Example 6-13 Using PROMPT and ACCEPT in Conjunction with Substitution Variables
As you have seen in Example 6-12, "Prompting for and Accepting Input", SQL*Plus automatically generates a prompt for a value when you use a substitution variable. You can replace this prompt by including PROMPT and ACCEPT in the script with the query that references the substitution variable. First clear the buffer with:
CLEAR BUFFER
To create such a file, enter the following:
INPUT
PROMPT Enter a valid employee ID PROMPT For Example 145, 206 ACCEPT ENUMBER NUMBER PROMPT 'Employee ID. :' SELECT FIRST_NAME, LAST_NAME, SALARY FROM EMP_DETAILS_VIEW WHERE EMPLOYEE_ID=&ENUMBER;
Save this file as PROMPT2. Next, run this script. SQL*Plus prompts for the value of ENUMBER using the text you specified with PROMPT and ACCEPT:
START PROMPT2
SQL*Plus prompts you to enter an Employee ID:
Enter a valid employee ID For Example 145, 206 Employee ID. : |
205
old 3: WHERE EMPLOYEE_ID=&ENUMBER new 3: WHERE EMPLOYEE_ID= 205 Department Report FIRST_NAME LAST_NAME SALARY -------------------- ------------------------- ---------- Shelley Higgins 12000 |
What would happen if you typed characters instead of numbers? Since you specified NUMBER after the variable name in the ACCEPT command, SQL*Plus will not accept a non-numeric value:
Try entering characters instead of numbers to the prompt for "Employee ID.", SQL*Plus will respond with an error message and prompt you again to re-enter the correct number:
START PROMPT2
When SQL*Plus prompts you to enter an Employee ID, enter the word "one" instead of a number:
Enter a valid employee ID For Example 145, 206 Employee ID. : |
one
SP2-0425: "one" is not a valid number |
If you want to display a message on the user's screen and then have the user press Return after reading the message, use the SQL*Plus command PAUSE. For example, you might include the following lines in a script:
PROMPT Before continuing, make sure you have your account card. PAUSE Press RETURN to continue.
In iSQL*Plus, PAUSE displays a Next Page button. Users must click Next Page to continue.
If you want to clear the screen before displaying a report (or at any other time), include the SQL*Plus CLEAR command with its SCREEN clause at the appropriate point in your script, using the following format:
CLEAR SCREEN
In iSQL*Plus, click the Clear button.
Before continuing to the next section, reset all columns to their original formats and headings by entering the following command:
CLEAR COLUMNS
Bind variables are variables you create in SQL*Plus and then reference in PL/SQL or SQL. If you create a bind variable in SQL*Plus, you can use the variable as you would a declared variable in your PL/SQL subprogram and then access the variable from SQL*Plus. You can use bind variables for such things as storing return codes or debugging your PL/SQL subprograms.
Because bind variables are recognized by SQL*Plus, you can display their values in SQL*Plus or reference them in PL/SQL subprograms that you run in SQL*Plus.
You create bind variables in SQL*Plus with the VARIABLE command. For example
VARIABLE ret_val NUMBER
This command creates a bind variable named ret_val with a datatype of NUMBER. See the VARIABLE command for more information. (To list all bind variables created in a session, type VARIABLE without any arguments.)
You reference bind variables in PL/SQL by typing a colon (:) followed immediately by the name of the variable. For example
:ret_val := 1;
To change this bind variable in SQL*Plus, you must enter a PL/SQL block. For example:
BEGIN :ret_val:=4;END;/
PL/SQL procedure successfully completed. |
This command assigns a value to the bind variable named ret_val.
To display the value of a bind variable in SQL*Plus, you use the SQL*Plus PRINT command. For example:
PRINT RET_VAL
RET_VAL
----------
4
|
This command displays a bind variable named ret_val. See PRINT for more information about displaying bind variables.
SQL*Plus REFCURSOR bind variables allow SQL*Plus to fetch and format the results of a SELECT statement contained in a PL/SQL block.
REFCURSOR bind variables can also be used to reference PL/SQL cursor variables in stored procedures. This enables you to store SELECT statements in the database and reference them from SQL*Plus.
A REFCURSOR bind variable can also be returned from a stored function.
Example 6-14 Creating, Referencing, and Displaying REFCURSOR Bind Variables
To create, reference and display a REFCURSOR bind variable, first declare a local bind variable of the REFCURSOR datatype
VARIABLE employee_info REFCURSOR
Next, enter a PL/SQL block that uses the bind variable in an OPEN... FOR SELECT statement. This statement opens a cursor variable and executes a query. See the PL/SQL User's Guide and Reference for information on the OPEN command and cursor variables.
In this example we are binding the SQL*Plus employee_info bind variable to the cursor variable.
BEGIN OPEN :employee_info FOR SELECT EMPLOYEE_ID, SALARY FROM EMP_DETAILS_VIEW WHERE JOB_ID='SA_MAN' ; END; /
PL/SQL procedure successfully completed. |
The results from the SELECT statement can now be displayed in SQL*Plus with the PRINT command.
PRINT employee_info
EMPLOYEE_ID SALARY
----------- ----------
145 14000
146 13500
147 12000
148 11000
149 10500
|
The PRINT statement also closes the cursor. To reprint the results, the PL/SQL block must be executed again before using PRINT.
Example 6-15 Using REFCURSOR Variables in Stored Procedures
A REFCURSOR bind variable is passed as a parameter to a procedure. The parameter has a REF CURSOR type. First, define the type.
CREATE OR REPLACE PACKAGE cv_types AS TYPE EmpInfoTyp is REF CURSOR RETURN emp_details_view%ROWTYPE; procedure emp_cv (a IN OUT EmpInfoTyp); END cv_types; /
Package created. |
Next, create the stored procedure containing an OPEN... FOR SELECT statement.
CREATE OR REPLACE PROCEDURE EmpInfo_rpt (emp_cv IN OUT cv_types.EmpInfoTyp) AS BEGIN OPEN emp_cv FOR SELECT EMPLOYEE_ID, SALARY FROM EMP_DETAILS_VIEW WHERE JOB_ID='SA_MAN' ; END; /
Procedure created. |
Execute the procedure with a SQL*Plus bind variable as the parameter.
VARIABLE odcv REFCURSOR EXECUTE EmpInfo_rpt(:odcv)
PL/SQL procedure successfully completed. |
Now print the bind variable.
PRINT odcv
EMPLOYEE_ID SALARY
----------- ----------
145 14000
146 13500
147 12000
148 11000
149 10500
|
The procedure can be executed multiple times using the same or a different REFCURSOR bind variable.
VARIABLE pcv REFCURSOR EXECUTE EmpInfo_rpt(:pcv)
PL/SQL procedure successfully completed. |
PRINT pcv
EMPLOYEE_ID SALARY
----------- ----------
145 14000
146 13500
147 12000
148 11000
149 10500
|
Example 6-16 Using REFCURSOR Variables in Stored Functions
Create a stored function containing an OPEN... FOR SELECT statement:
CREATE OR REPLACE FUNCTION EmpInfo_fn RETURN - cv_types.EmpInfo IS resultset cv_types.EmpInfoTyp; BEGIN OPEN resultset FOR SELECT EMPLOYEE_ID, SALARY FROM EMP_DETAILS_VIEW WHERE JOB_ID='SA_MAN'; RETURN(resultset); END; /
Function created. |
Execute the function.
VARIABLE rc REFCURSOR EXECUTE :rc := EmpInfo_fn
PL/SQL procedure successfully completed. |
Now print the bind variable.
PRINT rc
EMPLOYEE_ID SALARY
----------- ----------
145 14000
146 13500
147 12000
148 11000
149 10500
|
The function can be executed multiple times using the same or a different REFCURSOR bind variable.
EXECUTE :rc := EmpInfo_fn
PL/SQL procedure successfully completed. |
|
 Copyright © 1996, 2003 Oracle Corporation All Rights Reserved. |
|