Caché ObjectScript Reference - InterSystems Documentation

Caché ObjectScript CommandsDescriptionTCOMMIT marks the successful end of a transaction initiated by the corresponding TSTART.TCOMMIT decrements the value of the $TLEVEL special variable. Caché terminates thetransaction only if $TLEVEL goes to 0. Usually this is when TCOMMIT has been calledas many times as TSTART. Changes made during nested transactions are not committeduntil $TLEVEL=0.Calling TCOMMIT when $TLEVEL is already 0 results in a error. Thiscan occur if you issue a TCOMMIT when no transaction is in progress, when the numberof TCOMMIT commands is larger than the number of TSTART commands, or followinga TROLLBACK command.ArgumentspcAn optional postconditional expression. Caché executes the command if the postconditionalexpression is true (evaluates to a non-zero numeric value). Caché does not execute the commandif the postconditional expression is false (evaluates to zero). For further details, referto Command Postconditional Expressions in Using Caché ObjectScript.ExamplesYou use TCOMMIT with the TROLLBACK and TSTART commands. See TROLLBACKand TSTART for examples of how to use these transaction processing commands together.NotesNested TSTART / TCOMMITCaché supports the nesting of the TSTART/TCOMMIT commands, so that modules canissue their TSTART/TCOMMIT pairs correctly, independent of any otherTSTART/TCOMMIT issued in the modules that called them or in the modules they call.The current nesting level of the transaction is tracked by the special variable $TLEVEL. Thetransaction is committed when the outermost matching TCOMMIT is issued; that is, when$TLEVEL goes back to 0.You can roll back individual nested transactions by calling TROLLBACK 1 or roll back allcurrent transactions by calling TROLLBACK. TROLLBACK rolls back the whole transactionthat is in effect — no matter how many levels of TSTART were issued — and sets$TLEVEL to 0.136 Caché ObjectScript Reference