postgreSQL常用命令

1.添加字段

ALTER TABLE "表名" ADD COLUMN "字段名" 屬性:varchar(255);

ALTER TABLE "XXX" ADD COLUMN "test" varchar(255) NOT NULL;

2.刪除字段

ALTER TABLE "表名" DROP COLUMN "字段名";

3.查詢X表中所有索引

select * from pg_indexes where tablename='表名'; 

4.創建索引

CREATE INDEX "索引名" ON "表名" USING btree(索引方法) ("字段名");

5.刪除索引

DROP INDEX "索引名";

6.創建唯一約束

ALTER TABLE "表名" ADD CONSTRAINT "約束名" UNIQUE ("約束字段");

7.刪除約束條件(刪除唯一鍵, 外鍵, 檢查鍵, )

ALTER TABLE "表名" DROP CONSTRAINT "約束鍵名";

8.新增外鍵

ALTER TABLE "表名" ADD CONSTRAINT "外鍵名" FOREIGN KEY ("外鍵字段") 
  REFERENCES "關聯表" ("關聯字段") ON DELETE SET NULL ON UPDATE NO ACTION;

9.新增sql檢查

ALTER TABLE "表名" ADD CONSTRAINT "檢查約束名" CHECK ((條件));
ALTER TABLE "res_user" ADD CONSTRAINT "yueshu" CHECK ((id < 10000000));