sp_unprepare (Transact-SQL)
Applies to: 
SQL Server
Azure SQL Managed Instance
Azure Synapse Analytics
Analytics Platform System (PDW)
Discards the execution plan created by the sp_prepare stored procedure. sp_unprepare is invoked by specifying ID = 15 in a tabular data stream (TDS) packet.
Syntax
sp_unprepare handle
[ ; ]
Arguments
handle
The handle value returned by sp_prepare. handle is int.
Examples
The following example prepares, executes, and unprepares a basic statement.
DECLARE @P1 INT;
EXEC sp_prepare @P1 OUTPUT,
N'@P1 NVARCHAR(128), @P2 NVARCHAR(100)',
N'SELECT database_id, name FROM sys.databases WHERE name = @P1 AND state_desc = @P2';
EXEC sp_execute @P1, N'tempdb', N'ONLINE';
EXEC sp_unprepare @P1;