In PostgreSQL, the DELETE statement is used to remove rows from a table. This can be done conditionally (based on a WHERE clause) to delete specific rows, or without conditions to remove all rows in a table. Proper use of DELETE ensures that only the desired data is removed, while cautio...
CREATE TYPE table_count AS (table_name TEXT, num_rows INTEGER); 2、进行创建一个存储过程 代码语言:javascript 代码运行次数:0 运行 AI代码解释 CREATE OR REPLACE FUNCTION count_em_all (limitNum INTEGER) RETURNS SETOF table_count AS ' DECLARE the_count RECORD; -- 当前行数 t_name RECORD; -...
postgresql大表分批次删除 [root@localhost ~]# cat /root/delete_big_table.sh #!/bin/bash #$1对应表名,$2对应主键列,$3对应一次删除多少行 i=`psql -h 127.0.0.1 -U postgres -d tenant_1011046 -c "select ceil(count(1)/${3}::float) from ${1} where platcreatetime < '2023-04-30 23...
If theWHEREclause is absent, the effect is to delete all rows in the table. The result is a valid, but empty table. Tip:TRUNCATEis aPostgreSQL extension that provides a faster mechanism to remove all rows from a table. By default,DELETEwill delete rows in the specified table and all its...
When to Partition a Table什么时候需要分区表,官网的2个建议如下: Tables greater than 2GB should always be considered for partitioning. Tables containing historical data, in which new data is added into the newest partition. A typical example is a historical table where only the current month's da...
] ) [ INHERITS ( parent_table [, ... ] ) ] [ WITH OIDS | WITHOUT OIDS ] [ ON COMMIT { PRESERVE ROWS | DELETE ROWS | DROP } ] [ TABLESPACE tablespace ]column_constraint 可以是以下选项之一:[ CONSTRAINT constraint_name ] { NOT NULL | NULL | UNIQUE [ USING INDEX TABLESPACE tablespac...
*重命名一个表: alter table [表名A] rename to [表名B]; *删除一个表: drop table [表名]; [表内基本操作]=== *在已有的表里添加字段: alter table [表名] add column [字段名] [类型]; *删除表中的字段: alter table [表名] drop column [字段名]; *重命名一个字段: ...
You are now connected to database"test"asuser"postgres".test=# create tabletb_mytps(i int,namevarchar(32))tablespace mytbs;CREATETABLE 插入实验数据 代码语言:javascript 复制 insert intotb_mytps(i,name)values(2,'name2');insert intotb_mytps(i,name)values(3,'name3');insert intotb_mytps...
删除表格 Drop table 表名1) 模式操作创建模式 CREATE SCHEMA 模式名();删除模式 DROP SCHEMA 模式名2) 查找根据条件筛查数据 Select 列名 from 表名 where 筛选条件根据条件删除数据 Delete from 表名 where 筛选条件内连接 SELECT 表名1.列名, 表名2.列名FROM 表1INNER JOIN 表2ON 条件左外连接 SELECT 表...
pg_read_all_stats pg_stat_scan_tables pg_read_server_files pg_write_server_files pg_execute_server_program pg_signal_backend(9rows)Time:0.955ms 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 但它确实是存在的,它默认拥有: ...