altertablebas_cm_tenant_verificationdropcolumnifexistsverify_type; 修改/添加 列默认值 altertabletrace_code_batchaltercolumnexpected_quantitysetdefault0; ALTER TABLE trace_env ALTER COLUMN value set not null; 删除 列默认值 ALTERTABLEtable_nameALTERCOLUMNcolumn_nameDROPDEFAULT; ALTER TABLE trace_planting_...
alter sequence"t_user_ID_seq"restartwith1increment by1;--创建主键序列 drop indexifexists"t_user_pkey";alter table"t_user"add constraint"t_user_pkey"primarykey("ID"); 根据已有表结构创建表 代码语言:javascript 代码运行次数:0 运行 AI代码解释 create tableifnot exists新表(like 旧表 including i...
*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: alter table [表名] rename column [字段名A] to [字段名B]; *给一个字段设置缺省值: alter table [表名] alter column [字段名] set ...
IF EXISTS (SELECT * FROM information_schema.columns WHERE table_name = 't_knowledge_base' AND column_name = 'lock_level') THEN ALTER TABLE t_knowledge_base ALTER COLUMN lock_level set default '0'; ELSE ALTER TABLE t_knowledge_base ADD COLUMN lock_level int2 DEFAULT 0; END IF; end; ...
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: alter table [表名] rename column [字段名A] to [字段名B]; *给一个字段设置缺省值: alter table [表名] alter column [字段名] set default [新的默认值]; ...
ALTER FUNCTION 修改一个函数的定义。 ALTERFUNCTIONname([type[,...]])RENAMETOnew_nameALTERFUNCTIONname([type[,...]])OWNERTOnew_owner 复制 ALTER GROUP 修改一个用户组。 ALTERGROUPgroupnameADDUSERusername[,...]ALTERGROUPgroupnameDROPUSERusername[,...]ALTERGROUPgroupnameRENAMETOnew_name ...
COMMENT ON COLUMN public.t_user.update_time IS '更新时间'; -- 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"); ...
PostgreSQL ALTER TABLE examples Let’s create a new table called links for practicing with the ALTER TABLE statement. DROP TABLE IF EXISTS links; CREATE TABLE links ( link_id serial PRIMARY KEY, title VARCHAR (512) NOT NULL, url VARCHAR (1024) NOT NULL ); To add a new column named acti...
drop table [表名];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:alter table [表名] rename column [字段名A] to [字段名B];给一个字段设置缺省值:alter table [表名] alter column [字段名] ...
ALTER TABLE修改表的定义。ALTER TABLE [ ONLY ] name [ * ] action [, ... ] ALTER TABLE [ ONLY ] name [ * ] RENAME [ COLUMN ] column TO new_column ALTER TABLE name RENAME TO new_name其中action 可以是以选项之一:ADD [ COLUMN ] column_type [ column_constraint [ ... ] ] DROP [...