我需要在SQL server上编写一个查询,以获得特定表中的列列表,其相关数据类型(长度)以及它们是否不为空。我已经做到了这么多。
但现在我还需要得到,在同一个表中,对一个列- TRUE,如果该列是一个主键。
我该怎么做呢?
我的期望输出是:
Column name | Data type | Length | isnull | Pk
我需要在SQL server上编写一个查询,以获得特定表中的列列表,其相关数据类型(长度)以及它们是否不为空。我已经做到了这么多。
但现在我还需要得到,在同一个表中,对一个列- TRUE,如果该列是一个主键。
我该怎么做呢?
我的期望输出是:
Column name | Data type | Length | isnull | Pk
当前回答
select
c.name as [column name],
t.name as [type name],
tbl.name as [table name]
from sys.columns c
inner join sys.types t
on c.system_type_id = t.system_type_id
inner join sys.tables tbl
on c.object_id = tbl.object_id
where
c.object_id = OBJECT_ID('YourTableName1')
and
t.name like '%YourSearchDataType%'
union
(select
c.name as [column name],
t.name as [type name],
tbl.name as [table name]
from sys.columns c
inner join sys.types t
on c.system_type_id = t.system_type_id
inner join sys.tables tbl
on c.object_id = tbl.object_id
where
c.object_id = OBJECT_ID('YourTableName2')
and
t.name like '%YourSearchDataType%')
union
(select
c.name as [column name],
t.name as [type name],
tbl.name as [table name]
from sys.columns c
inner join sys.types t
on c.system_type_id = t.system_type_id
inner join sys.tables tbl
on c.object_id = tbl.object_id
where
c.object_id = OBJECT_ID('YourTableName3')
and
t.name like '%YourSearchDataType%')
order by tbl.name
根据一个数据库中三个不同表的搜索数据类型,搜索哪个列在哪个表中。这个查询可以扩展到'n'个表。
其他回答
在SQL 2012中,你可以使用:
EXEC sp_describe_first_result_set N'SELECT * FROM [TableName]'
这将为您提供列名及其属性。
为了避免某些列的重复行,请使用user_type_id而不是system_type_id。
SELECT
c.name 'Column Name',
t.Name 'Data type',
c.max_length 'Max Length',
c.precision ,
c.scale ,
c.is_nullable,
ISNULL(i.is_primary_key, 0) 'Primary Key'
FROM
sys.columns c
INNER JOIN
sys.types t ON c.user_type_id = t.user_type_id
LEFT OUTER JOIN
sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
LEFT OUTER JOIN
sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
WHERE
c.object_id = OBJECT_ID('YourTableName')
只需将YourTableName替换为实际的表名-适用于SQL Server 2005及更高版本。
如果您正在使用模式,请将YourTableName替换为YourSchemaName。YourTableName,其中YourSchemaName是实际的模式名,YourTableName是实际的表名。
为了确保获得正确的长度,需要将unicode类型视为一种特殊情况。参见下面的代码。
更多信息请参见:https://msdn.microsoft.com/en-us/library/ms176106.aspx
SELECT
c.name 'Column Name',
t.name,
t.name +
CASE WHEN t.name IN ('char', 'varchar','nchar','nvarchar') THEN '('+
CASE WHEN c.max_length=-1 THEN 'MAX'
ELSE CONVERT(VARCHAR(4),
CASE WHEN t.name IN ('nchar','nvarchar')
THEN c.max_length/2 ELSE c.max_length END )
END +')'
WHEN t.name IN ('decimal','numeric')
THEN '('+ CONVERT(VARCHAR(4),c.precision)+','
+ CONVERT(VARCHAR(4),c.Scale)+')'
ELSE '' END
as "DDL name",
c.max_length 'Max Length in Bytes',
c.precision ,
c.scale ,
c.is_nullable,
ISNULL(i.is_primary_key, 0) 'Primary Key'
FROM
sys.columns c
INNER JOIN
sys.types t ON c.user_type_id = t.user_type_id
LEFT OUTER JOIN
sys.index_columns ic ON ic.object_id = c.object_id AND ic.column_id = c.column_id
LEFT OUTER JOIN
sys.indexes i ON ic.object_id = i.object_id AND ic.index_id = i.index_id
WHERE
c.object_id = OBJECT_ID('YourTableName')
在查询编辑器中选择表名并按Alt+F1,它将带来表的所有信息。
你可以使用查询:
select COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH,
NUMERIC_PRECISION, DATETIME_PRECISION,
IS_NULLABLE
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME='TableName'
以获得除Pk信息之外的所有元数据。