5 Using Scripts in SQL*Plus

Writing Scripts with a System Editor

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 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.

EDIT SALES

COLUMN LAST_NAME HEADING 'LAST NAME'
COLUMN SALARY HEADING 'MONTHLY SALARY' FORMAT $99,999
COLUMN COMMISSION_PCT HEADING 'COMMISSION %' FORMAT 90.90
SELECT LAST_NAME, SALARY, COMMISSION_PCT
FROM EMP_DETAILS_VIEW
WHERE JOB_ID='SA_MAN';

Listing the Buffer Contents

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.

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.

Editing the Current Line

The SQL*Plus CHANGE command enables you to edit the current line. Various actions determine which line is the current line:

• LIST a given line to make it 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.

SELECT EMPLOYEE_ID, LAST_NAME, JO_ID, SALARY
FROM EMP_DETAILS_VIEW
WHERE JOB_ID='SA_MAN';

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.

CHANGE /JO_ID/JOB_ID

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 4-4, "Entering a SQL*Plus Command (not in iSQL*Plus)". (If you have left SQL*Plus and started again since performing Example 4-4, "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.

Appending Text to a Line

To add text to the end of a line in the buffer, use the APPEND command.

1. Use the LIST command (or the line number) to list the line you want to change.

2. 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.

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

Adding a New Line

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

INPUT

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

Deleting Lines

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.

Using the REMARK Command

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_PCT
FROM EMP_DETAILS_VIEW
WHERE JOB_ID='SA_MAN';

Using /*...*/

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_PCT
FROM EMP_DETAILS_VIEW
/* Include only salesmen.*/
WHERE JOB_ID='SA_MAN'; 

Using - -

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

Notes on Placing Comments

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:

1. 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.
   

2. 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.

3. 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.

4. 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_VIEW
   WHERE 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.

Running a Script as You Start SQL*Plus

To run a script as you start SQL*Plus, use one of the following options:

• Follow the SQLPLUS command with your username, a slash, a space, @, and the name of the file:

  SQLPLUS HR @SALES
  

  SQL*Plus starts, prompts for your password and runs the script.

• Include your username as the first line of the file. Follow the SQLPLUS command with @ and the filename. SQL*Plus starts, prompts for your password and runs the file.

Where and How to Use Substitution Variables

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.

SELECT &GROUP_COL, MAX(&NUMBER_COL) MAXIMUM
FROM &TABLE
GROUP 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';

Avoiding Unnecessary Prompts for Values

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 5-9, "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.

SET VERIFY OFF

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

Restrictions

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.

System Variables and iSQL*Plus Preferences

The following system variables, specified with the SQL*Plus SET command or in iSQL*Plus preferences, affect substitution variables:

SET CONCAT

SET DEFINE

SET ESCAPE

SET NUMFORMAT

SET NUMWIDTH

SET VERIFY ON

See SET for more information about system variables.

iSQL*Plus Input Required Screen

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:

Receiving a Substitution Variable Value

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.

CLEAR BUFFER

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

Customizing Prompts for Substitution Variable

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.

CLEAR BUFFER

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;

START PROMPT2

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

Sending a Message and Accepting Return as Input

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.

Clearing the Screen

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

Creating Bind Variables

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.)

Referencing Bind Variables

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.

Displaying Bind Variables

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.