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

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。

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')

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')
SELECT COLUMN_NAME, IS_NULLABLE, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH FROM information_schema.columns WHERE table_name = '<name_of_table_or_view>'

在上面的语句中运行SELECT *,以查看information_schema. schema是什么。列的回报。

这个问题之前已经回答过了- https://stackoverflow.com/a/11268456/6169225