如何使用FireDac组件在MS SQL Server上获取最后插入的ID？

Question

with FireDac, How to get last inserted id on ms sql server? thanks

Answer 1

Make the that id to a identity column and then get it by Using

SELECT SCOPE_IDENTITY()

after the insert statement

Please refer the following links

http://msdn.microsoft.com/en-us/library/ms190315.aspx

Answer 2

Use auto-incremented field type

http://www.da-soft.com/anydac/docu/Auto-Incremental_Fields.html

This would provide for code like

DataSet.Insert;
.... 
DataSet.Post; 
id := DataSet.FieldByName('ID').AsInteger;

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Another approach might be crafting proper SQL statements like described at

• http://en.wikipedia.org/wiki/Insert_(SQL)#Retrieving_the_key
• SQL Server - Return value after INSERT
• Best way to get identity of inserted row?

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AnyDAC author also suggests a special method to fetch DBMS-specific toolings via http://docs.embarcadero.com/products/rad_studio/firedac/uADCompClient_TADCustomConnection_GetLastAutoGenValue@String.html

But all those post-factum requests with SELECT @@identity or SELECT SCOPE_IDENTITY are fragile and dangerous. When you insert data into table A, its triggers may insert data into related tables B and C, and identity would recall C's autoinc, rather than table where you started inserting at.