如何使用查询为现有表生成 SQL 创建脚本
此问题涉及为已存在的表生成 SQL CREATE 脚本。虽然提供的语法准确地解决了此任务，但可以对响应进行一些改进。
改进的响应：
这可能对您有帮助。该脚本生成索引、外键 (FK)、主键 (PK) 以及任何表的通用结构。该脚本由一个查询部分组成，该部分收集表信息并连接适当的 CREATE 语句。
例如，考虑以下表定义：
CREATE TABLE [dbo].[WorkOut] ( [WorkOutID] [bigint] IDENTITY(1,1) NOT NULL, [TimeSheetDate] [datetime] NOT NULL, [DateOut] [datetime] NOT NULL, [EmployeeID] [int] NOT NULL, [IsMainWorkPlace] [bit] NOT NULL, [DepartmentUID] [uniqueidentifier] NOT NULL, [WorkPlaceUID] [uniqueidentifier] NULL, [TeamUID] [uniqueidentifier] NULL, [WorkShiftCD] [nvarchar](10) NULL, [WorkHours] [real] NULL, [AbsenceCode] [varchar](25) NULL, [PaymentType] [char](2) NULL, [CategoryID] [int] NULL, [Year] AS (datepart(year,[TimeSheetDate])), CONSTRAINT [PK_WorkOut] PRIMARY KEY CLUSTERED ([WorkOutID] ASC) ) ON [PRIMARY] ALTER TABLE [dbo].[WorkOut] ADD CONSTRAINT [DF__WorkOut__IsMainW__2C1E8537] DEFAULT ((1)) FOR [IsMainWorkPlace] ALTER TABLE [dbo].[WorkOut] WITH CHECK ADD CONSTRAINT [FK_WorkOut_Employee_EmployeeID] FOREIGN KEY([EmployeeID]) REFERENCES [dbo].[Employee] ([EmployeeID]) ALTER TABLE [dbo].[WorkOut] CHECK CONSTRAINT [FK_WorkOut_Employee_EmployeeID]
查询脚本可用于生成用于重新创建表的 DDL 语句。
Declare @table_name SYSNAME = 'dbo.WorkOut'
Declare
@object_name SYSNAME,
@object_id INT
SELECT
@object_name = '[' + s.name + '].[' + o.name + ']',
@object_id = o.[object_id]
FROM sys.objects o WITH (NOWAIT)
JOIN sys.schemas s WITH (NOWAIT) ON o.[schema_id] = s.[schema_id]
WHERE s.name + '.' + o.name = @table_name
AND o.[type] = 'U'
AND o.is_ms_shipped = 0
DECLARE @SQL NVARCHAR(MAX) = ''
;WITH index_column AS
(
SELECT
ic.[object_id],
ic.index_id,
ic.is_descending_key,
ic.is_included_column,
c.name
FROM sys.index_columns ic WITH (NOWAIT)
JOIN sys.columns c WITH (NOWAIT) ON ic.[object_id] = c.[object_id] AND ic.column_id = c.column_id
WHERE ic.[object_id] = @object_id
),
fk_columns AS
(
SELECT
k.constraint_object_id,
cname = c.name,
rcname = rc.name
FROM sys.foreign_key_columns k WITH (NOWAIT)
JOIN sys.columns rc WITH (NOWAIT) ON rc.[object_id] = k.referenced_object_id AND rc.column_id = k.referenced_column_id
JOIN sys.columns c WITH (NOWAIT) ON c.[object_id] = k.parent_object_id AND c.column_id = k.parent_column_id
WHERE k.parent_object_id = @object_id
)
SELECT @SQL = 'CREATE TABLE ' + @object_name + CHAR(13) + '(' + CHAR(13) + STUFF((
SELECT CHAR(9) + ', [' + c.name + '] ' +
CASE WHEN c.is_computed = 1
THEN 'AS ' + cc.[definition]
ELSE UPPER(tp.name) +
CASE WHEN tp.name IN ('varchar', 'char', 'varbinary', 'binary', 'text')
THEN '(' + CASE WHEN c.max_length = -1 THEN 'MAX' ELSE CAST(c.max_length AS VARCHAR(5)) END + ')'
WHEN tp.name IN ('nvarchar', 'nchar', 'ntext')
THEN '(' + CASE WHEN c.max_length = -1 THEN 'MAX' ELSE CAST(c.max_length / 2 AS VARCHAR(5)) END + ')'
WHEN tp.name IN ('datetime2', 'time2', 'datetimeoffset')
THEN '(' + CAST(c.scale AS VARCHAR(5)) + ')'
WHEN tp.name IN ('decimal', 'numeric')
THEN '(' + CAST(c.[precision] AS VARCHAR(5)) + ',' + CAST(c.scale AS VARCHAR(5)) + ')'
ELSE ''
END +
CASE WHEN c.collation_name IS NOT NULL THEN ' COLLATE ' + c.collation_name ELSE '' END +
CASE WHEN c.is_nullable = 1 THEN ' NULL' ELSE ' NOT NULL' END +
CASE WHEN dc.[definition] IS NOT NULL THEN ' DEFAULT' + dc.[definition] ELSE '' END +
CASE WHEN ic.is_identity = 1 THEN ' IDENTITY(' + CAST(ISNULL(ic.seed_value, '0') AS CHAR(1)) + ',' + CAST(ISNULL(ic.increment_value, '1') AS CHAR(1)) + ')' ELSE '' END
END + CHAR(13)
FROM sys.columns c WITH (NOWAIT)
JOIN sys.types tp WITH (NOWAIT) ON c.user_type_id = tp.user_type_id
LEFT JOIN sys.computed_columns cc WITH (NOWAIT) ON c.[object_id] = cc.[object_id] AND c.column_id = cc.column_id
LEFT JOIN sys.default_constraints dc WITH (NOWAIT) ON c.default_object_id != 0 AND c.[object_id] = dc.parent_object_id AND c.column_id = dc.parent_column_id
LEFT JOIN sys.identity_columns ic WITH (NOWAIT) ON c.is_identity = 1 AND c.[object_id] = ic.[object_id] AND c.column_id = ic.column_id
WHERE c.[object_id] = @object_id
ORDER BY c.column_id
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 2, CHAR(9) + ' ')
+ ISNULL((SELECT CHAR(9) + ', CONSTRAINT [' + k.name + '] PRIMARY KEY (' +
(SELECT STUFF((
SELECT ', [' + c.name + '] ' + CASE WHEN ic.is_descending_key = 1 THEN 'DESC' ELSE 'ASC' END
FROM sys.index_columns ic WITH (NOWAIT)
JOIN sys.columns c WITH (NOWAIT) ON c.[object_id] = ic.[object_id] AND c.column_id = ic.column_id
WHERE ic.is_included_column = 0
AND ic.[object_id] = k.parent_object_id
AND ic.index_id = k.unique_index_id
FOR XML PATH(N''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 2, ''))
+ ')' + CHAR(13)
FROM sys.key_constraints k WITH (NOWAIT)
WHERE k.parent_object_id = @object_id
AND k.[type] = 'PK'), '') + ')' + CHAR(13)
+ ISNULL((SELECT (
SELECT CHAR(13) +
'ALTER TABLE ' + @object_name + ' WITH'
+ CASE WHEN fk.is_not_trusted = 1
THEN ' NOCHECK'
ELSE ' CHECK'
END +
' ADD CONSTRAINT [' + fk.name + '] FOREIGN KEY('
+ STUFF((
SELECT ', [' + k.cname + ']'
FROM fk_columns k
WHERE k.constraint_object_id = fk.[object_id]
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 2, '')
+ ')' +
' REFERENCES [' + SCHEMA_NAME(ro.[schema_id]) + '].[' + ro.name + '] ('
+ STUFF((
SELECT ', [' + k.rcname + ']'
FROM fk_columns k
WHERE k.constraint_object_id = fk.[object_id]
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 2, '')
+ ')'
+ CASE
WHEN fk.delete_referential_action = 1 THEN ' ON DELETE CASCADE'
WHEN fk.delete_referential_action = 2 THEN ' ON DELETE SET NULL'
WHEN fk.delete_referential_action = 3 THEN ' ON DELETE SET DEFAULT'
ELSE ''
END
+ CASE以上是如何为现有表生成 SQL CREATE 脚本？的详细内容。更多信息请关注PHP中文网其他相关文章！
