@文心快码postgresql alter table add constraint 文心快码 在PostgreSQL中,ALTER TABLE语句用于修改现有表的结构,例如添加或删除列、添加或删除约束等。下面是对你问题的详细回答: ALTER TABLE语句的用途: ALTER TABLE语句在PostgreSQL中用于修改已存在的表的结构。这包括添加或删除列、修改列的数据类型、添加或删除约束...
Introduction to the PostgreSQL ADD COLUMN statement To add a new column to an existing table, you use the ALTER TABLE ADD COLUMN statement as follows: ALTER TABLE table_name ADD COLUMN new_column_name data_type constraint; In this syntax: First, specify the name of the table to which you...
grant select on tablename to zhangsan;//授予zhangsan用户查看指定表的权限 grant drop on tablename to zhangsan;//授予删除表的权限 grant insert on tablename to zhangsan;//授予插入的权限 grant update on tablename to zhangsan;//授予修改表的权限 grant insert(id) on tablename to zhangsan; grant u...
grant select,insert,update,deleteon all tablesinschemapublicto 用户名; 撤回权限 代码语言:javascript 代码运行次数:0 运行 AI代码解释 #撤回在public模式下的权限 revoke select on all tablesinschemapublicfrom 用户名;#撤回在information_schema模式下的权限 revoke select on all tablesinschema information_schem...
ALTER TABLE t_test DROP COLUMN t1; 如果t1字段被另外的表外键引用,直接执行删除会报错,需要使用cascade删除外键的依赖 ALTER TABLE t_test DROP COLUMN t1 cascade; 增加约束 ALTER TABLE t_test ADDCHECK(t2 >0);表示t2得大于0ALTER TABLE t_test ADD CONSTRAINT unique_test_keyUNIQUE(t1);表示t1是唯一约...
grant all on database 数据库名 to 用户名; #授权可操作的模式和权限 -- 授权 grant select on all tables in schema public to 用户名; -- 授权 GRANT ALL ON TABLE public.user TO mydata; GRANT SELECT, UPDATE, INSERT, DELETE ON TABLE public.user TO mydata_dml; ...
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...
strSQL :='ALTER TABLE'||TG_RELNAME||'_'||curMM||'add constraintuk_tu_phone_'||curMM||'unique(phone);';EXECUTE strSQL; END IF;--插入数据到子分区表 strSQL :='INSERT INTO'||TG_RELNAME||'_'||curMM||'SELECT $1.*'; EXECUTE strSQL USING NEW; ...
CREATE TABLE david=# 3.2 创建分区表 david=# create table tbl_partition_201211 ( check ( join_date >= DATE '2012-11-01' AND join_date ) INHERITS (tbl_partition); CREATE TABLE david=# create table tbl_partition_201212 ( check ( join_date >= DATE '2012-12-01' AND join_date ...
语法：ALTER TABLE table_name ADD CONSTRAINT unique_constraint_name UNIQUE ;功能：确保指定列中的值唯一。添加 CHECK 约束：语法：ALTER TABLE table_name ADD CONSTRAINT check_constraint_name CHECK ;功能：为表添加条件约束，确保列中的数据满足特定的条件。添加主键：语法：ALTER TABLE table_name ...