Heim >Datenbank >MySQL-Tutorial >Wie erstelle ich SQL CREATE-Skripte für vorhandene Tabellen?
So generieren Sie SQL-Erstellungsskripts für vorhandene Tabellen mit Abfrage
Diese Frage bezieht sich auf die Generierung von SQL-CREATE-Skripts für bereits vorhandene Tabellen. Obwohl die bereitgestellte Syntax diese Aufgabe genau löst, können einige Verbesserungen an der Antwort vorgenommen werden.
Verbesserte Antwort:
Möglicherweise ist dies hilfreich für Sie. Dieses Skript generiert Indizes, Fremdschlüssel (FKs), einen Primärschlüssel (PK) und die gemeinsame Struktur für jede Tabelle. Das Skript besteht aus einem Abfrageteil, der Tabelleninformationen sammelt und die entsprechenden CREATE-Anweisungen verkettet.
Berücksichtigen Sie beispielsweise die folgende Tabellendefinition:
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]
Ein Abfrageskript kann zum Generieren verwendet werden die DDL-Anweisung, um die Tabelle neu zu erstellen.
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
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