SQL 获取具有类型名称的表列

Question

我已经成功地从下面的查询中获取了表和列的信息。

是否有任何方便的方法来获取带有 nvarchar(20)、numeric(14,2)、varchar(max) 等描述的类型名称，而不是大量的 CASE 语句？

SELECT 
    o.name AS TableName,
    c.name AS ColumnName,
    t.name + 
    CASE 
        WHEN t.name LIKE '%char' THEN '(' + 
            CASE 
                WHEN c.max_length = -1 THEN 'max' 
                ELSE CONVERT(varchar(10), c.max_length / CASE WHEN t.name LIKE 'n%' THEN 2 ELSE 1 END) 
            END + ')'
        WHEN t.name IN ('numeric', 'decimal') THEN '(' + CONVERT(varchar(4), c.precision) + ',' + CONVERT(varchar(4), c.scale) + ')'
        -- WHEN .... many other types
        ELSE ''
    END AS TypeName
FROM 
    sys.objects o 
    INNER JOIN sys.columns c ON o.object_id = c.object_id
    INNER JOIN sys.types t ON t.system_type_id = c.system_type_id AND t.user_type_id = c.user_type_id
WHERE
    o.is_ms_shipped = 0
ORDER BY
    o.name,
    c.column_id

编辑

sp_help 和信息架构返回的名称不是 nvarchar(20)、numeric(14,2)、varchar(max)

Answer 1

我使用这个视图来记录数据库......你可以使用它并使用 data_type 和 Length/Precision

/****** Object:  View [dbo].[vw_DataDictionary]    Script Date: 17/07/2015 10:24:04 AM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

ALTER VIEW [dbo].[vw_DataDictionary]
AS
SELECT     TOP (100) PERCENT tb.name AS Table_Name, CAST(ept.value AS nvarchar(200)) AS Table_Description, CAST(c.name AS nvarchar(200)) AS Column_Name, 
                      CAST(ep.value AS nvarchar(200)) AS column_Description, t.name AS data_type, c.is_nullable AS Is_Null, object_definition(c.default_object_id) AS default_text, 
                      c.max_length AS Length, c.precision AS numeric_precision, c.scale AS numeric_scale, c.column_id
FROM         sys.columns AS c LEFT OUTER JOIN
                      sys.tables AS tb ON tb.object_id = c.object_id LEFT OUTER JOIN
                      sys.types AS t ON c.system_type_id = t.system_type_id AND c.user_type_id = t.user_type_id LEFT OUTER JOIN
                      sys.extended_properties AS ept ON ept.major_id = tb.object_id AND ept.minor_id = 0 AND ept.name = 'MS_Description' LEFT OUTER JOIN
                      sys.extended_properties AS ep ON ep.major_id = c.object_id AND ep.minor_id = c.column_id AND ep.name = 'MS_Description'
WHERE     (tb.type = 'U') AND (tb.name <> 'sysdiagrams')
ORDER BY Table_Name, c.column_id

GO

Answer 2

对于 SQL Server 2008 R2，我已通过CASE 声明类型如下：

SQL Fiddle

SELECT 
    DB_NAME() AS DatabaseName, 
    SCHEMA_NAME(o.schema_id) AS SchemaName, 
    o.name AS ObjectName, 
    c.name AS ColumnName, 
    RTRIM(o.type) AS ObjectType, 
    t.name AS TypeName,
    c.max_length AS Length,

    -- The logic is implemented in this column
    t.name + 
    CASE 
        -- (max) for char type / binary only
        WHEN (t.name LIKE '%char%' OR t.name LIKE '%binary') AND c.max_length = -1 THEN '(max)'
        -- (n) where n = length / 2 for nchar and nvarchar
        WHEN t.name LIKE '%char%' AND LEFT(t.name, 1) = 'n' THEN '(' + CONVERT(varchar, c.max_length / 2) + ')' 
        -- (n) where n = length
        WHEN t.name LIKE '%char%' OR t.name LIKE '%binary' THEN '(' + CONVERT(varchar, c.max_length) + ')' 
        -- (p,s) where p = precision, s = scale
        WHEN t.name IN ('numeric', 'decimal') THEN '(' + CONVERT(varchar, c.precision) + ',' + CONVERT(varchar, c.scale) + ')'
        -- (s) where s = scale
        WHEN t.name IN ('time', 'datetime2', 'datetimeoffset') THEN '(' + CONVERT(varchar, c.scale) + ')'
        ELSE '' 
    END AS Type
FROM 
    sys.objects o 
    inner join sys.columns c on o.object_id = c.object_id
    inner join sys.types t on c.system_type_id = t.system_type_id and c.user_type_id = t.user_type_id
WHERE 1 = 1
    AND o.is_ms_shipped = 1

Answer 3

这应该对你有帮助，来自here

DECLARE @tblname VARCHAR(300)

SET @tblname = 'tblname'

SELECT o.list AS ColumnsDescription
FROM sysobjects so
CROSS APPLY (
    SELECT '  [' + column_name + '] ' + data_type + CASE data_type
            WHEN 'sql_variant'
                THEN ''
            WHEN 'text'
                THEN ''
            WHEN 'ntext'
                THEN ''
            WHEN 'xml'
                THEN ''
            WHEN 'decimal'
                THEN '(' + cast(numeric_precision AS VARCHAR) + ', ' + cast(numeric_scale AS VARCHAR) + ')'
            ELSE coalesce('(' + CASE 
                        WHEN character_maximum_length = - 1
                            THEN 'MAX'
                        ELSE cast(character_maximum_length AS VARCHAR)
                        END + ')', '')
            END + ' ' + CASE 
            WHEN EXISTS (
                    SELECT id
                    FROM syscolumns
                    WHERE object_name(id) = so.NAME
                        AND NAME = column_name
                        AND columnproperty(id, NAME, 'IsIdentity') = 1
                    )
                THEN 'IDENTITY(' + cast(ident_seed(so.NAME) AS VARCHAR) + ',' + cast(ident_incr(so.NAME) AS VARCHAR) + ')'
            ELSE ''
            END + ' ' + (
            CASE 
                WHEN IS_NULLABLE = 'No'
                    THEN 'NOT '
                ELSE ''
                END
            ) + 'NULL ' + CASE 
            WHEN information_schema.columns.COLUMN_DEFAULT IS NOT NULL
                THEN 'DEFAULT ' + information_schema.columns.COLUMN_DEFAULT
            ELSE ''
            END + ', '
    FROM information_schema.columns
    WHERE table_name = so.NAME
    ORDER BY ordinal_position
    FOR XML PATH('')
    ) o(list)
LEFT JOIN information_schema.table_constraints tc ON tc.Table_name = so.NAME
    AND tc.Constraint_Type = 'PRIMARY KEY'
CROSS APPLY (
    SELECT '[' + Column_Name + '], '
    FROM information_schema.key_column_usage kcu
    WHERE kcu.Constraint_Name = tc.Constraint_Name
    ORDER BY ORDINAL_POSITION
    FOR XML PATH('')
    ) j(list)
WHERE xtype = 'U'
    AND NAME = @tblname

您可以根据需要解析结果。

Answer 4

SELECT 
        COLUMN_NAME, 
        CASE 
        WHEN DATA_TYPE ='decimal' THEN DATA_TYPE+ '('+cast (NUMERIC_PRECISION as Varchar)+ ','+cast (NUMERIC_SCALE as Varchar)+ ')'
        WHEN CHARACTER_MAXIMUM_LENGTH is null THEN DATA_TYPE + cast ('' as Varchar) 
        ELSE DATA_TYPE + '('+ cast (CHARACTER_MAXIMUM_LENGTH as Varchar)+')' END AS QuantityText
    
    FROM 
        INFORMATION_SCHEMA.COLUMNS
    WHERE 
        TABLE_NAME = 'table_name' and TABLE_SCHEMA = 'dbo'
        order by COLUMN_NAME