alter table "t_user" add constraint "t_user_pkey" primary key ("ID"); 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 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); 1....
ALTER TABLE 表名 ADD 约束类型(列名); 1. 1. 添加非空约束 ALTER TABLE 表名 MODIFY COLUMN 列名 类型 NOT NULL; 2. 添加默认约束 ALTER TABLE 表名 MODIFY COLUMN 列名 类型 DEFAULT 值; 3.添加检查约束(MySQL不支持检查约束) ALTER TABLE 表名 ADD CONSTRAINT 约束名 CHECK(约束条件); 3. 添加主键 #...
selectempid,keyask,value::textascardidfrom(selectempid,row_to_json(row(cardid,cardid2,cardid3,cardid4))asnfromemployee t )asrjoinlateral json_each_text(r.n)on(valueisnotnullandvalue!='') 6.不支持+=,不支持++ 7.列不存在则添加 ALTER TABLE table1 ADD if not exists name text; 8.用a...
-- 创建自增序列alter sequence "t_user_ID_seq" restart with 1 increment by 1; -- 创建主键序列 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 ind...
How to add column if not exists on PostgreSQL WithPostgres 9.6this can be done using the optionif not exists ALTER TABLE table_name ADD COLUMN IF NOT EXISTS column_name INTEGER; https://stackoverflow.com/questions/12597465/how-to-add-column-if-not-exists-on-postgresql...
test=> load'$libdir/plugins/pgtt’ LOAD CREATE /*GLOBAL*/ TEMPORARY TABLE t2 ( c1 serial PRIMARY KEY, c2 VARCHAR (50) UNIQUE NOT NULL, c3 boolean DEFAULT false ); 但不支持外键 代码语言:javascript 复制 CREATE /*GLOBAL*/ TEMPORARY TABLE t3 ( c1 int, FOREIGN KEY (c1) REFERENCES tb1...
(创建表)createsequenceifnotexistsdms_file_label_new_file_id_seqincrementby1minvalue1no maxvaluestartwith1;altertabledms_file_label_newaltercolumn"id"setdefaultnextval('dms_file_label_new_file_id_seq'); (创建序列,并赋值给id)CREATEINDEXidx_dms_file_label_label_classify2ONdms_file_label_newUSING...
CREATE TABLE IF NOT EXISTS pathman_config_params ( partrel REGCLASS NOT NULL PRIMARY KEY, enable_parent BOOLEAN NOT NULL DEFAULT TRUE, auto BOOLEAN NOT NULL DEFAULT TRUE, init_callback TEXT DEFAULT NULL, spawn_using_bgw BOOLEAN NOT NULL DEFAULT FALSE); This table stores optional parameters wh...
查看sql卡住的task特别是alter table相关的sql,先在master查看是否有锁select * from pg_stat_activity;然后看是否有相互等待的sessionSELECT...上语句加上锁了select * from pg_stat_activityselect * from pg_locks where pid = {xxx}(这里的pid就是pg_stat_activity...的procpid) select * from pg_class ...
-- PostgreSQL支持事务性DDL BEGIN; ALTER TABLE account ADD COLUMN new_column INT; UPDATE account SET new_column = 1 WHERE id = 100; COMMIT; 电子商务数据分析 电子商务平台需要进行复杂的数据分析,如用户行为分析、销售预测等。 PostgreSQL 的窗口函数和物化视图等特性可以有效地支持这些操作,提供更快的数据...