您可以命名特定对象以获取更多信息。使用+运算符还将列出表的约束和索引。postgres=# \d+ example_tbl Table "public.example_tbl"Column | Type | Collation | Nullable | Default | Storage | Compression | Stats target | Description---+---+---+---+---+---+---+---+---id | ...
FROM pg_catalog.pg_attrdef d WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef) ELSE '' END as column_default_value, CASE WHEN a.attnotnull = true THEN 'NOT NULL' ELSE 'NULL' END as column_not_null, a.attnum as attnum, e.max_attnum as max_attnum FR...
PostgreSQL supports a TIMESTAMP data type that is used to store the DateTime values in the database. In PostgreSQL, “NULL” is used as the column’s default value, if no default value is explicitly declared. However, if a particular value is assigned as the column’s default value, ...
CREATE[ORREPLACE]FUNCTIONname([[argmode][argname]argtype[{DEFAULT|=}default_expr][,...]])[RETURNSrettype|RETURNSTABLE(column_name column_type[,...])]{LANGUAGElang_name|TRANSFORM{FORTYPEtype_name}[,...]|WINDOW|IMMUTABLE|STABLE|VOLATILE|[NOT]LEAKPROOF|CALLEDONNULLINPUT|RETURNSNULLONNULLINPUT|...
Allow ALTER TABLE to add a column with a non-null default without doing a table rewrite (Andrew Dunstan, Serge Rielau) This is enabled when the default value is a constant.PostgreSQL 11版本的一些新特性PostgreSQL11: 新增三个默认角色 PostgreSQL11: 可通过GRNAT权限下放的四个系统函数 PostgreSQL...
hrdb=# COMMENTONCOLUMNtab_num.v5IS'大整型最小范围'; COMMENT hrdb=# COMMENTONCOLUMNtab_num.v6IS'大整型最大范围'; COMMENT hrdb=#--描述数据类型 hrdb=# \d+ tab_num Table"public.tab_num" Column| Type | Collation | Nullable |Default| Storage | Stats target | Description ...
这是比较原始的方式,但是这种方式是一直被支持的,更方便的方式就是对这些操作的封装。psqlorm需要一个已经初始化好的pg连接对象,在内部去通过pg执行sql。 constpsqlorm =require('psqlorm');constpg =require('pg');constpgdb =newpg.Pool({database:'DATABASE',user:'USERNAME',password:'PASSWORD',host:'lo...
alter table [表名] alter column [字段名] drop default; *修改表中的某行某列的数据: update [表名] set [目标字段名]=[目标值] where [该行特征]; *删除表中某行数据: delete from [表名] where [该行特征]; delete from [表名]; // 删空整个表 ...
方法1:superuser 通过alter system关键字命令设置,使用方法:alter system set parameter = value,修改后需要重新启动数据库服务器才能够生效。 说明: alter system 修改后只是将该参数写到postgresql.auto.conf文件里,故需要重启才可以生效。 方法2:手动配置到postgresql.conf里,修改后重启数据库生效。
例:create table postgtest (id serial primary key,title varchar(255) not null, content text check(length(content) > 3),is_draft boolean default true , create_date timestamp default 'now'); 插入 INSERT INTO TABLE_NAME (column1, column2, column3,...columnN)VALUES (value1, value2, value...