In the above snippet, the CASE statement is used to add the gender description to the output: This is how theSimple CASE Statementworks in PostgreSQL. Example 3: How to Use the CASE Statement With Aggregate Functions in Postgres? Postgres allows us to use the simple and searched CASE statem...
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...
[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;...
tg02 before insert on digoal for each row execute procedure debug(); CREATE TRIGGER postgres=# create trigger tg03 after insert on digoal for each row execute procedure debug(); CREATE TRIGGER postgres=# create trigger tg04 after insert on digoal for each statement execute procedure debug(); ...
Example 4: Dealing With Multiple Conditions 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 eva...
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 ...
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 ...
For example, to make a single multistatement transaction commit asynchronously when the default is the opposite, issue SET LOCAL synchronous_commit TO OFF within the transaction. Table 19.1 summarizes the capabilities of the synchronous_commit settings. Table 19.1. synchronous_commit Modes synchronous_...
操作符AND和OR是可交换的,也就是说,你可以交换左右操作数而不影响结果。 2. 比较函数和操作符 常见的比较操作符都可用,如Table 9-1所示。 Table 9-1. 比较操作符 Note: !=操作符在分析器阶段被转换成<>。不能把!=和<>操作符实现为做不同的事。
*/ switch (check_log_duration(msec_str, was_logged)) { case 1: ereport(LOG, (errmsg("duration: %s ms", msec_str), errhidestmt(true))); break; case 2: ereport(LOG, (errmsg("duration: %s ms statement: %s", msec_str, query_string), errhidestmt(true), errdetail_execute(parsetr...