delete from tablename; 2.适合删除大量数据,速度快 TRUNCATE TABLE tablename; 3.若该表有外键,要用级联方式删所有关联的数据 TRUNCATE TABLE tablename CASCADE; 直接删表: drop table if exists +表名
这段代码会遍历所有表名,并逐个执行DROP TABLE IF EXISTS语句来删除它们。quote_ident函数用于安全地引用表名,以防止SQL注入攻击。CASCADE选项会删除表的同时删除与该表关联的所有对象(如索引、外键等)。 确认所有表已被删除: 再次执行步骤2中的查询来确认所有表是否已被删除。如果查询结果为空,则说明所有表都已被...
drop index if exists "t_user_pkey"; alter table "t_user" add constraint "t_user_pkey" primary key ("ID"); 根据已有表结构创建表 create table if not exists 新表 (like 旧表 including indexes including comments including defaults); 删除表 drop table if exists "t_template" cascade; 查询注...
DROP TABLE IF EXISTS"public"."tb_111a7f37a7f04d6fae334f198ed6a474"cascade; CREATE TABLE"public"."tb_111a7f37a7f04d6fae334f198ed6a474"( "current_phase_a"float8, "current_phase_b"float8, "current_phase_c"float8, "voltage_phase_a"float8, "voltage_phase_b"float8, "voltage_phase...
) AS pretty_sizes 删除表中数据: 1.适用数据量较小的情况 delete from tablename; 2.适合删除大量数据,速度快 TRUNCATE TABLE tablename; 3.若该表有外键,要用级联方式删所有关联的数据 TRUNCATE TABLE tablename CASCADE; 直接删表: drop table if exists +表名...
CREATE OR REPLACE FUNCTION drop_all_tables_in_schema(schema_name TEXT) RETURNS void AS $$ DECLARE r RECORD; BEGIN FOR r IN (SELECT tablename FROM pg_tables WHERE schemaname = schema_name) LOOP EXECUTE 'DROP TABLE IF EXISTS ' || quote_ident(r.tablename) || ' CASCADE'; ...
"adi"."device_status" IS '状态:0 离线,1 在线'; COMMENT ON TABLE "public"."adi" IS '状态类、型表'; --创建视图 v_adis DROP VIEW IF EXISTS v_adis CASCADE; CREATE OR REPLACE VIEW "public"."v_adis" AS SELECT split_part(string_agg(concat(countInfo.device_count, ''), ',') , ...
DROP FUNCTION IF EXISTS func_name (args) [Cascade | restrict]; In the above syntax: ● After theDROP FUNCTION IF EXISTstatement, we have to write the function’s name that we want to drop. ● We can optionally use theCASCADEandRESTRICToptions. ...
ERROR: cannot drop table student_info because other objects depend on it DETAIL: table class_info depends on table student_info HINT: Use DROP ... CASCADE to drop the dependent objects too. testdb=# drop table student_info cascade;
DROPTRIGGER[IFEXISTS]trigger_nameONtable_name[RESTRICT|CASCADE]; IF EXISTS 可以避免触发器不存在时的错误提示;CASCADE 表示级联删除依赖于该触发器的对象,RESTRICT 表示如果存在依赖于该触发器的对象返回错误,默认为 RESTRICT。 我们将 employees 表上的触发器 trg_employees_change 删除: ...