此文档主要描述Postgre数据库，基于Red Hat Enterprise Linux Server release 6.5 的操作系统上安装Postgre...
test=# create table tbl_default(a int not null,b varchar(12) not null); CREATE TABLE test=# alter table tbl_default alter COLUMN b set default 'try me'; ALTER TABLE test=# \d tbl_default Table "public.tbl_default" Column | Type | Modifiers ---+---+--- a | integer | not nu...
test=# create table tbl_default(a int not null,b varchar(12) not null); CREATE TABLE test=# alter table tbl_default alter COLUMN b set default 'try me'; ALTER TABLE test=# \d tbl_default Table "public.tbl_default" Column | Type | Modifiers ---+---+--- a | integer | not nu...
postgres=# \help create table Command: CREATE TABLE Description: define a new table Syntax: CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXISTS ] table_name ( [ { column_name data_type [ STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN | DEFAULT } ]...
CREATE TABLE dbname2=# create table t2 (aint) tablespace tbs1; CREATE TABLE dbname2=# create table t3 (aint) tablespace tbs2; CREATE TABLE 如果您想知道组成表的文件的确切位置,可以使用 oid2name: oid2name是一个实用程序,可帮助管理员检查 PostgreSQL 使用的文件结构。
postgres=# create tableadd_c_d_in_ms(id int,a1 text,a2 text,a3 text,a4 text,a5 text,a6 text,a7 text,a8 text notnulldefault'wangshuo');CREATETABLETime:72.243ms postgres=# select oid,relname,relnatts from pg_class where relname='add_c_d_in_ms';oid|relname|relnatts---+---+---...
ALTERTABLEtbl_nameALTERCOLUMNcol_nameSETDEFAULTdefault_val; Example 1: Setting a Column’s Default Value While Table Creation Let’s create a new sample table named “std_details” with three columns: std_id, std_name, std_age: CREATETABLEemp_details( ...
TABLENAME - tablename quoted as literal to use in function calls (required for timescale) The template syntax is just a suggestion but curly braces shouldnt conflict with any SQL. Example Templates --Default ValueCREATE TABLE {TABLE}({COLUMNS},PRIMARY KEY({PK_COLUMNS}));--PostgreSQL 10 Parti...
Allows you to click the button and configure relevant parameters to create a field. Name The name of the field. Field type The data type of the field. Length setting The length of the field. You can specify the length for fields only of specific data types. Default value The defau...
ALTERDATABASEnameSETconfiguration_parameter{TO|=}{value|DEFAULT} 对于随后连接的会话,PostgreSQL 将会使用该命令设置的值覆盖postgresql.conf文件或者命令行参数的值。注意,只有超级用户或者数据库的拥有者才能修改数据库的默认会话变量。 例如,以下语句将会默认禁用数据库 newdb 中的索引扫描: ...