How do you run a loop in PL SQL?
PL/SQL – FOR LOOP Statement
- The initial step is executed first, and only once. …
- Next, the condition, i.e., initial_value .. …
- After the body of the for loop executes, the value of the counter variable is increased or decreased.
- The condition is now evaluated again.
How do you loop through a cursor in PL SQL?
In each loop iteration, the cursor FOR LOOP statement fetches a row from the result set into its loop index. If there is no row to fetch, the cursor FOR LOOP closes the cursor. The cursor is also closed if a statement inside the loop transfers control outside the loop, e.g., EXIT and GOTO , or raises an exception.
How do you repeat a string in Oracle?
RPAD(string, LENGTH(string)*n, string) where n is the number of times you want string repeated.
How do I create a loop in Oracle SQL query?
Basic Loop Statement
The execution block starts with keyword ‘LOOP’ and ends with the keyword ‘END LOOP’. The exit condition should be given inside this execution block so that control exit from the loop. It needs EXIT keyword to be given explicitly in the execution part to exit from the loop.
How do you end a loop in PL SQL?
Note: You must follow these steps while using PL/SQL Exit Loop.
- Initialize a variable before the loop body.
- Increment the variable in the loop.
- You should use EXIT WHEN statement to exit from the Loop. Otherwise the EXIT statement without WHEN condition, the statements in the Loop is executed only once.
Why do we use loops in PL SQL?
PL/SQL for loop is used when when you want to execute a set of statements for a predetermined number of times. The loop is iterated between the start and end integer values. The counter is always incremented by 1 and once the counter reaches the value of end integer, the loop ends.
What is for loop cursor?
The cursor FOR LOOP statement implicitly declares its loop index as a record variable of the row type that a specified cursor returns, and then opens a cursor. With each iteration, the cursor FOR LOOP statement fetches a row from the result set into the record.
What is difference between simple loop while loop & FOR loop?
for loop: for loop provides a concise way of writing the loop structure. Unlike a while loop, a for statement consumes the initialization, condition and increment/decrement in one line thereby providing a shorter, easy to debug structure of looping.
What is trigger in PL SQL with examples?
Triggers are stored programs, which are automatically executed or fired when some events occur. Triggers are, in fact, written to be executed in response to any of the following events − A database manipulation (DML) statement (DELETE, INSERT, or UPDATE) A database definition (DDL) statement (CREATE, ALTER, or DROP).
What is Instr in SQL?
INSTR() is a string function in standard query language (SQL) which returns the starting position or location of a substring or pattern in the given input string. … SQL INSTR() function returns the first occurrence of a substring in an input string.
How do I remove a character from a string in Oracle?
The Oracle TRIM function is used to remove all leading or trailing characters (or both) from a character string. If trim_character or trim_source is a character literal, then it is necessary to enclose it in single quotation marks. When no trim_character is specified, then the default value is a blank space.
What are Oracle strings?
Oracle String Function. The Oracle String functions manipulate the character strings more effectively. … The DECOMPOSE() function returns a Unicode string from the given string. DUMP() The DUMP() function returns the string datatype code, length in bytes and some internal representation of the given string.
What are the three kinds of loops in PL SQL?
PL/SQL provides three different kinds of loop constructs:
- The simple or infinite loop.
- The FOR loop (numeric and cursor)
- The WHILE loop.
How do I loop a stored procedure in Oracle?
“FOR LOOP” statement is best suitable when you want to execute a code for a known number of times rather than based on some other conditions. In this loop, the lower limit and the higher limit will be specified and as long as the loop variable is in between this range, the loop will be executed.
What are the types of loops in PL SQL?
There are 4 types of PL/SQL Loops.
- Basic Loop / Exit Loop.
- While Loop.
- For Loop.
- Cursor For Loop.