Column| Type | Collation | Nullable |Default ---+---+---+---+--- a |integer| |notnull| b |integer| | | c | text | | | Indexes: "t2_pkey"PRIMARYKEY, btree (a) Foreign-keyconstraints: "t2_b_fkey"FOREIGNKEY(b)REFERENCESt1(a) Disabled internal triggers: "RI_ConstraintTrigger_...
SELECTcolumn_name, data_type, is_nullable, column_default FROMinformation_schema.columns WHEREtable_name =''; ci_database_test01=#SELECTcolumn_name, data_type, is_nullable, column_default ci_database_test01-#FROMinformation_schema.columns ci_database_test01-#WHEREtable_name ='pg_range'; col...
file_fdw 也新增了一个 REJECT_LIMIT 选项 (还新增了on_error 和 log_verbosity)。 temporal FOREIGN KEY contraints:https://www.depesz.com/2024/10/03/waiting-for-postgresql-18-add-temporal-foreign-key-contraints/[6] 小结 简而言之,18 也是一个值得期待的大版本,让我们拭目以待! 参考 http://git....
如字符串varcharcol.is_nullable,-- 字段是否可空casewhencol.udt_name='varchar'thenconcat(col.character_maximum_length)whencol.udt_name='timestamp'thenconcat(col.datetime_precision)whencol.udt_name='date'thenconcat(col.datetime_precision)whencol.udt_name='numeric'orcol.udt_namelike'int%'thenconcat...
Partition key: HASH (userid) Indexes:"userinfo_pkey"PRIMARY KEY, btree (userid) Number of partitions: 4 (Use \d+ to list them.) 查看子表,发现子表上也有了主键。 francs=> \d userinfo_p0 Table"francs.userinfo_p0"Column |Type|Collation|Nullable|Default ...
(2,100) i;INSERT099postgres=# analyze t;ANALYZEpostgres=#createindex iont(b);CREATEINDEXpostgres=# \d tTable"public.t"Column|Type|Collation|Nullable|Default---+---+---+---+---a | integer | | |b | text | | |Indexes:"i" btree (b) postgres=# select relpages,reltuples from p...
test=# \d invoicesTable"public.invoices "Column|Type|Collation|Nullable|Default---+---+---+---+---invoice_number|integer||notnull|issued_on|date||notnull|now()Indexes:"invoices_pkey "PRIMARYKEY,btree(invoice_number)Numberofchildtables:1(Use\d+tolist them.)test=# \d government_invoice...
ORACLE允许任何一种数据类型的字段为空,除了以下两种情况: 1、主键字段(primary key), 2、定义时 oracle insert null sql table 转载 小咪咪 2月前 18阅读 postgresql 查询所有null的字段的件数 在.net 2.0 中,提供了 Nullable 的范型,通过它,我们可以为基础类型如 int 等赋予 null 的值,这样我们就...
test=#\dinvoicesTable"public.invoices "Column|Type|Collation|Nullable|Default---+---+---+---+---invoice_number|integer||notnull|issued_on|date||notnull|now()Indexes:"invoices_pkey "PRIMARYKEY,btree(invoice_number)Numberofchildtables:1(Use\d+tolistthem.)test=#\dgovernment_invoicesTable"...
test=# \d empTable "mytest.emp"Column | Type | Collation | Nullable | Default---+---+---+---+---empno | numeric | | not null |ename | character varying(10) | | |job | character varying(9) | | |mgr | numeric | | |hiredate | date | | |sal | numeric(7,2) | | |...