MySQL Stored procedure Learning

1, the use of cursors

BEGIN    DECLAREDoneINT DEFAULT 0; DECLAREUseridINT; DECLARERsCURSOR  for SELECT' UID ' fromSinbegin_userWHEREService= 0;/*Defining Cursors*/    DECLARE CONTINUEHANDLER forSQLSTATE'02000' SETDone= 1;/*Exception Handling*/    OPENRs/*Open Cursor*/        FETCH NEXT  fromRs intouserid; REPEAT/*traversing a data table*/            IF  notDone Then                UPDATESinbegin_userSETService= 1 WHEREUid=userid; END IF; FETCH NEXT  fromRs intouserid; UNTIL DoneENDREPEAT; CLOSERs/*Close Cursors*/END

2. Use of If condition judgment

Grammar

IF  Then commands    [ELSEIF expression then commands]   [ELSE commands]   END IF;

Sample code

IFCurrentlingqi>= 1800  Then    UPDATESocialrelationSETLingqi= 1800 WHERENodeName=Shizuname;ELSE     UPDATESocialrelationSETLingqi=Lingqi+  - WHERENodeName=Shizuname;END IF;

MySQL Stored procedure Learning