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
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。
其他回答
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')
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。
我刚刚做了marc_s“presentation ready”:
SELECT
c.name 'Column Name',
t.name 'Data type',
IIF(t.name = 'nvarchar', c.max_length / 2, c.max_length) 'Max Length',
c.precision 'Precision',
c.scale 'Scale',
IIF(c.is_nullable = 0, 'No', 'Yes') 'Nullable',
IIF(ISNULL(i.is_primary_key, 0) = 0, 'No', 'Yes') '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')
将另一个答案放入环中,这将给你这些列和更多:
SELECT col.TABLE_CATALOG AS [Database]
, col.TABLE_SCHEMA AS Owner
, col.TABLE_NAME AS TableName
, col.COLUMN_NAME AS ColumnName
, col.ORDINAL_POSITION AS OrdinalPosition
, col.COLUMN_DEFAULT AS DefaultSetting
, col.DATA_TYPE AS DataType
, col.CHARACTER_MAXIMUM_LENGTH AS MaxLength
, col.DATETIME_PRECISION AS DatePrecision
, CAST(CASE col.IS_NULLABLE
WHEN 'NO' THEN 0
ELSE 1
END AS bit)AS IsNullable
, COLUMNPROPERTY(OBJECT_ID('[' + col.TABLE_SCHEMA + '].[' + col.TABLE_NAME + ']'), col.COLUMN_NAME, 'IsIdentity')AS IsIdentity
, COLUMNPROPERTY(OBJECT_ID('[' + col.TABLE_SCHEMA + '].[' + col.TABLE_NAME + ']'), col.COLUMN_NAME, 'IsComputed')AS IsComputed
, CAST(ISNULL(pk.is_primary_key, 0)AS bit)AS IsPrimaryKey
FROM INFORMATION_SCHEMA.COLUMNS AS col
LEFT JOIN(SELECT SCHEMA_NAME(o.schema_id)AS TABLE_SCHEMA
, o.name AS TABLE_NAME
, c.name AS COLUMN_NAME
, i.is_primary_key
FROM sys.indexes AS i JOIN sys.index_columns AS ic ON i.object_id = ic.object_id
AND i.index_id = ic.index_id
JOIN sys.objects AS o ON i.object_id = o.object_id
LEFT JOIN sys.columns AS c ON ic.object_id = c.object_id
AND c.column_id = ic.column_id
WHERE i.is_primary_key = 1)AS pk ON col.TABLE_NAME = pk.TABLE_NAME
AND col.TABLE_SCHEMA = pk.TABLE_SCHEMA
AND col.COLUMN_NAME = pk.COLUMN_NAME
WHERE col.TABLE_NAME = 'YourTableName'
AND col.TABLE_SCHEMA = 'dbo'
ORDER BY col.TABLE_NAME, col.ORDINAL_POSITION;
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。