Example 1: How Does the Searched CASE Statement Work in Postgres? In this example, we will apply the CASE statement on the “author_info” table, whose data is shown in the following snippet: SELECT*FROMauthor_
Only rows where the department is 'Sales' are included in the result. Example 3: Using CASE WHEN in an UPDATE Statement Code: -- Update employee bonuses based on their performance UPDATE employees SET bonus = CASE WHEN performance_rating = 'Excellent' THEN 1000 WHEN performance_rating = 'Goo...
Use the IF-THEN-ELSIF instead of a simple IF-ELSE if you have to evaluate multiple conditions. In such a case, if the specified condition is true, the associated statement within that branch will be executed. If all the specified conditions are evaluated to FALSE, then the control will be...
[ELSEstatements ]ENDCASE; 3.LOOPS of PL/SQL 3.1 LOOP for LOOP, it is often used with EXIT ,CONTINUE ,which is just like "break" and "continue" in C for a loop. the grammar is like below: [ <> ]LOOPstatementsENDLOOP[label]; example is: LOOP-- some computationsEXITWHENcount >100;...
视图触发器的创建分类 :(INSTEAD OF) (INSERT | UPDATE | DELETE) (FOR EACH ROW) (WHEN NEW.? and,or OLD.? ... other boolean express ...)(before | after) (INSERT | UPDATE | DELETE) (FOR EACH STATEMENT) (WHEN BOOLEAN express except NEW or OLD or columns) 分类...
A MOVE statement sets FOUND true if it successfully repositions the cursor, false otherwise. A FOR or FOREACH statement sets FOUND true if it iterates one or more times, else false. FOUND is set this way when the loop exits; inside the execution of the loop, FOUND is not modified by ...
In this case, you can use the CREATE TABLE AS statement which provides more functionality than the SELECT INTO statement. PostgreSQL SELECT INTO examples We will use the film table from the sample database for the demonstration. 1) Basic PostgreSQL SELECT INTO statement example The following ...
Example: \sleep 10 ms 7. 脚本weight 当使用多个脚本时,可以为每个脚本设置weight,即权重。如果不设置,默认为1. pgbench -f ./test1.sql@100 -f ./test2.sql@200 那么有1/3的机会调用test1.sql,有2/3的机会调用test2.sql 详见man pgbench 或 https://www.postgresql.org/docs/9.6/static/pgbench...
procedure_demo-# LANGUAGE plpgsql ;CREATEPROCEDUREprocedure_demo=#calldisplay_message('This is my test case');NOTICE: Procedure Parameter: This is my test case msg---This is my test case (1 row) 3. Using transaction control procedure_demo=#CREATEORREPLACE...
说明:Return the given string suitably quoted to be used as an identifier in an SQL statement string. Quotes are added only if necessary (i.e., if the string contains non-identifier characters or would be case-folded). Embedded quotes are properly doubled. 对某一字符串加上两引号 ...