Learn how to use conditional logic in PostgreSQL with the IF statement. Includes syntax, examples, and tips for efficient conditional database operations. PostgreSQL IF Statement PostgreSQL does not have a direct IF statement for use within SQL queries. However, conditional logic can be achieved usi...
PostgreSQL可以不借助任何扩展实现对SQL日志的记录,主要依赖于两个参数,也即log_statement和log_min_duration_statement, 1,记录的sql类型 log_statement='all' 可以是none, ddl, mod, all 2,记录的sql执行时间阈值 log_min_duration_statement='1000',单位毫秒,记录超出该单位时间的log_statement中定义类型的SQL ...
if_statement_db=# select * from phone; 输出: id | phone_name | phone_type | phone_price ---+---+---+--- (0 rows) 作者:David Mbochi Njonge David is a back end developer with a major in computer science. He loves to solve problems using technology, learning new things, and ma...
可以查慢sql # - What to Log - log_duration = on # 导致每一个完成的语句的持续时间被记录 log_lock_waits = on # 等锁超时记录日志,超时时间参数 deadlock_timeout log_statement = 'mod' # mod记录所有ddl语句,外加数据修改语句例如INSERT, UPDATE、DELETE、TRUNCATE, 和COPY FROM log_replication_...
定位一个游标。 MOVE [ direction { FROM | IN } ] cursor_nameNOTIFY生成一个通知。NOTIFY namePREPARE创建一个准备好的查询。PREPARE plan_name [ (data_type [, ...] ) ] AS statementREINDEX重建索引。REINDEX { DATABASE | TABLE | INDEX } name [ FORCE ]...
postgres=# selectconcat('su','re'); 2、进入到服务端 数据库客户端会根据前后端协议将用户查询将信息发送到服务端,进入函数PostgresMain,然后进入exec_simple_query,exec_simple_query函数主要分为两部分,第一部分是查询分析,第二部分是查询执行,下面以下图进行说明查询分析: ...
ALTER MATERIALIZED VIEW IF EXISTS vvvRENAME TO vvvvvv UPDATE pgbench_accounts set abalance='8888882' WHERE aid='48'> ERROR: relation "vvv" does not existCONTEXT: SQL statement "REFRESH MATERIALIZED VIEW CONCURRENTLY vvv"PL/pgSQL function update_my_view() line 5 at SQL statement ...
You have two errors in your statement: There is no IF in SQL, you need to use a CASE expression String constants are defined using single quotes in SQL ('), double quotes are for identifiers select case when available_count < 5 then 'neni skladem' else 'na sklade' end as availabi...
Example #1: How to Use IF-THEN-ELSIF Statement in Postgres? Let’s create two variables and assign them some random values: DO $$ DECLARE first_val INT := 72; second_val INT := 50; BEGIN IF first_val < second_val THEN RAISE NOTICE 'first_val is less than second_val'; ...
PostgreSQL SELECT INTO Summary: in this tutorial, you will learn how to use the PostgreSQL SELECT INTO statement to create a new table from the result set of a query. If you want to select data into variables, check out the PL/pgSQL SELECT INTO statement. Introduction to PostgreSQL SELECT...