PostgreSQL支持的表级约束包括 UNIQUE(column1, ...),唯一约束,括号中的字段值或字段值的组合必须唯一。 PRIMARY KEY(column1, ...),主键约束,定义主键或者复合主键。 REFERENCES,定义外键约束。 CHECK,定义检查约束。 以下示例创建了员工表(employees) CREATETABLEemployees ( employee_idINTEGERNOTNULL, first_name...
删除已经建好的自增主键,通过 identity 方式重建(要求版本>=10) altertable"public".dim_shdistrict_info_testDROPCOLUMN"id"; altertable"public".dim_shdistrict_info_testADD"id"intgenerated alwaysasidentity(cache100startwith1incrementby1)primarykey; 四、解决方案 承接重现的问题,最终对插入数据的方式略做修...
ALTER [ COLUMN ] column_name DROP EXPRESSION [ IF EXISTS ] ALTER [ COLUMN ] column_name ADD GENERATED { ALWAYS | BY DEFAULT } AS IDENTITY [ ( sequence_options ) ] ALTER [ COLUMN ] column_name {SETGENERATED { ALWAYS | BY DEFAULT } |SETsequence_option | RESTART [ [ WITH ] restart ...
postgres=# \helpSELECTCommand:SELECTDescription:retrieve rows from a table or viewSyntax:[WITH[RECURSIVE]with_query[,...]]SELECT[ALL|DISTINCT[ON(expression[,...])]][*|expression[[AS]output_name][,...]][FROMfrom_item[,...]][WHEREcondition][GROUPBYgrouping_element[,...]][HAVINGcondition[...
postgres=# create database test;CREATEDATABASEpostgres=# alter database testsettablespace mytbs;ALTERDATABASEpostgres=# \c test You are now connected to database"test"asuser"postgres".test=# create tabletb_mytps(i int,namevarchar(32))tablespace mytbs;CREATETABLE ...
[ ONLY ] table_name [ * ] [ [ AS ]alias[ ( column_alias [, ...] ) ] ] SQL 语句 一个SQL 语句通常包含了关键字、标识符(字段)、常量、特殊符号等,下面是一个简单的 SQL 语句: SELECT id, name FROM runoob PostgreSQL 命令 ABORT
将RPM和源码安装两种方式的操作流程进行对比,会发现源码安装需要处理很多依赖问题的琐事,显然比较麻烦,这里个人更偏向官方推荐的RPM方式进行Postgresql安装搭建,省去很多钻牛角尖的时间。 参考资料 Linux部署postgresql并开启远程访问 - 掘金 (juejin.cn) # PostgreSQL在Linux下的两种安装方式 ...
# SET NULL 主表在 on delete/update 时,设置从表外键为 NULL。 # SET DEFAULT 主表在 on delete/update 时,设置从表外键为 DEFAULT(默认值)。 CREATE TABLE products ( product_no integer PRIMARY KEY, name text, price numeric ); CREATE TABLE orders ( order_id integer PRIMARY KEY, shipping_addres...
| | |job | character varying(9) | | |mgr | numeric | | |hiredate | date | | |sal | numeric(7,2) | | |comm | numeric(7,2) | | |deptno | numeric(2,0) | | |Indexes:"pk_emp" PRIMARY KEY, btree (empno)test=# \d pk_empIndex "mytest.pk_emp"Column | Type | Key?
tbinfo.comment AS table_comment, colinfo.attnum AS column_number, colinfo.attname AS column_name, CASE WHEN ((colinfo.typelen)::text = 'bigint'::text) THEN 'INT8'::character varying WHEN ((colinfo.typelen)::text = 'smallint'::text) THEN 'INT2'::character varying ...