MySQL INSERT INTO table SELECT FROM another_table, inside a PROCEDURE

Question

I have this MySQL procedure, that makes some loops into 2 tables, prepares the Data into tblResults and then insert all data (if no errors) into a huge table after delete all rows found between 2 dates.

The problem is that after the procedure finishes to run, I receive this warning:

Unsafe statement written to the binary log using statement format since BINLOG_FORMAT = STATEMENT. Statements writing to a table with an auto-increment column after selecting from another table are unsafe because the order in which rows are retrieved determines what (if any) rows will be written. This order cannot be predicted and may differ on master and the slave.

and as a result, if I have 250 distinct rows into tblResults table, the procedure insert 250 identical rows into final table. (usualy first or last row found in tblResults, multiplied by number of records from tblResults).

The SQL code look like this:

BEGIN
--  DECLARE bDone INT;

  DECLARE CustomerId INT;  
  DECLARE LocationId INT;
  DECLARE ContractId INT;
  DECLARE DatePeriod DATE;
  DECLARE SerialWeight DOUBLE;
  DECLARE Serial VARCHAR(150);
  DECLARE EnergyZone VARCHAR(5);
  DECLARE ConsDay DATE;
  DECLARE T0  DOUBLE;
  DECLARE T1  DOUBLE;
  DECLARE T2  DOUBLE;
  DECLARE T3  DOUBLE;
  DECLARE T4  DOUBLE;
  DECLARE T5  DOUBLE;
  DECLARE T6  DOUBLE;
  DECLARE T7  DOUBLE;
  DECLARE T8  DOUBLE;
  DECLARE T9  DOUBLE;
  DECLARE T10 DOUBLE;
  DECLARE T11 DOUBLE;
  DECLARE T12 DOUBLE;
  DECLARE T13 DOUBLE;
  DECLARE T14 DOUBLE;
  DECLARE T15 DOUBLE;
  DECLARE T16 DOUBLE;
  DECLARE T17 DOUBLE;
  DECLARE T18 DOUBLE;
  DECLARE T19 DOUBLE;
  DECLARE T20 DOUBLE;
  DECLARE T21 DOUBLE;
  DECLARE T22 DOUBLE;
  DECLARE T23 DOUBLE;
  DECLARE QtyEstimated DECIMAL(20,4);

  DECLARE QtyMeasured DECIMAL(20,4);
  DECLARE POD VARCHAR(50);

  DECLARE Quantity DECIMAL(20,4);
  DECLARE LocationCode VARCHAR(50);

  DECLARE rCustomerId INT; 
  DECLARE rLocationId INT;
  DECLARE rContractId INT;
  DECLARE rDate DATE;
  DECLARE rTime INT;
  DECLARE rQtyEstimated DECIMAL(20,4);
  DECLARE rQtyPredicted DECIMAL(20,4);
  DECLARE rQtyMeasured DOUBLE;
  DECLARE rCreateUser INT;
  DECLARE rUpdateUser INT;
  DECLARE rFirmaId INT;



  DECLARE curs CURSOR FOR  

    select 
      ec.CustomerId,
      ec.LocationId,
      ec.Id as ContractId,
      els.Date as DatePeriod,
      els.SerialWeight,
      ets.Serial,
      ets.EnergyZone,
      ets.Date as ConsDay,
      ets.T0,
      ets.T1,
      ets.T2,
      ets.T3,
      ets.T4,
      ets.T5,
      ets.T6,
      ets.T7,
      ets.T8,
      ets.T9,
      ets.T10,
      ets.T11,
      ets.T12,
      ets.T13,
      ets.T14,
      ets.T15,
      ets.T16,
      ets.T17,
      ets.T18,
      ets.T19,
      ets.T20,
      ets.T21,
      ets.T22,
      ets.T23,
      CASE substr(els.Date, 6, 2)
        WHEN '01' THEN ec.Estimated1 
        WHEN '02' THEN ec.Estimated2
        WHEN '03' THEN ec.Estimated3
        WHEN '04' THEN ec.Estimated4
        WHEN '05' THEN ec.Estimated5
        WHEN '06' THEN ec.Estimated6
        WHEN '07' THEN ec.Estimated7
        WHEN '08' THEN ec.Estimated8
        WHEN '09' THEN ec.Estimated9
        WHEN '10' THEN ec.Estimated10
        WHEN '11' THEN ec.Estimated11
        WHEN '12' THEN ec.Estimated12
        END as QtyEstimated 
    from EnergyLocationSeries els 
    left join EnergyTimeSeries ets ON ets.Serial = els.Serial and concat(substr(ets.Date, 1, 7), '-01') = els.Date 
    left join EnergyLocation el ON el.Code2 = els.LocationCode 
    left join EnergyContract ec ON (el.Id = ec.LocationId AND el.Codep = '') OR (ec.LocationId = (SELECT max(Id) FROM EnergyLocation WHERE Code2 = el.Codep) AND Codep !='') -- AND ec.`Status` != 'Reziliat' 
    where els.Date = MTH and els.EnergyZone = ZONE 
     order by ets.Date ASC LIMIT 10;


  DECLARE pods_cursor CURSOR FOR 

      SELECT els.LocationCode, els.Quantity 
      FROM EnergyLocation el 
      RIGHT JOIN EnergyLocationSeries els ON els.LocationCode = el.Code2 OR els.LocationCode = el.Codep 
      LEFT JOIN EnergyContract ec on ec.LocationId = el.Id 
      WHERE el.Code2 IS NULL; 



  DECLARE result CURSOR FOR 
      SELECT `CustomerId`, `LocationId`, `ContractId`, `Date`, `Time`, `QtyEstimated`, `QtyPredicted`, `QtyMeasured`, `CreateUser`, `UpdateUser`, `FirmaId` 
      FROM tblResults ORDER BY CustomerId, ContractId ASC; 


  DROP TABLE IF EXISTS tblResultsErrors;
  CREATE TABLE IF NOT EXISTS tblResultsErrors  (
    `POD` INT(11) NULL DEFAULT NULL,
    `QtyMeasured` DECIMAL(20,4) NULL DEFAULT NULL
  );



  DROP TABLE IF EXISTS tblResults;
  CREATE TABLE IF NOT EXISTS tblResults  (
    `CustomerId` INT(11) NULL DEFAULT NULL,
    `LocationId` INT(11) NULL DEFAULT NULL,
    `ContractId` INT(11) NULL DEFAULT NULL,
    `Date` DATE NULL DEFAULT NULL,
    `Time` SMALLINT(6) NULL DEFAULT NULL,
    `QtyEstimated` DECIMAL(20,4) NULL DEFAULT NULL,
    `QtyPredicted` DECIMAL(20,4) NULL DEFAULT NULL,
    `QtyMeasured` DOUBLE NULL DEFAULT NULL,
    `CreateUser` VARCHAR(32) NULL DEFAULT NULL,
    `UpdateUser` VARCHAR(32) NULL DEFAULT NULL,
    `FirmaId` INT(11) NULL DEFAULT NULL 
  );





  OPEN curs;
  BEGIN 
        DECLARE bDone INT;
        DECLARE CONTINUE HANDLER FOR NOT FOUND SET bDone = 1;  

      SET bDone = 0;
      REPEAT
        FETCH curs INTO       
          CustomerId,
          LocationId,
          ContractId,
          DatePeriod,
          SerialWeight,
          Serial,
          EnergyZone,
          ConsDay,
          T0,
          T1,
          T2,
          T3,
          T4,
          T5,
          T6,
          T7,
          T8,
          T9,
          T10,
          T11,
          T12,
          T13,
          T14,
          T15,
          T16,
          T17,
          T18,
          T19,
          T20,
          T21,
          T22,
          T23,
          QtyEstimated;

        IF bDone = 0 THEN 

           INSERT INTO tblResults VALUES 
              (CustomerId,LocationId,ContractId,ConsDay,1,QtyEstimated,0,(T0   * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,2,QtyEstimated,0,(T1   * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,3,QtyEstimated,0,(T2   * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,4,QtyEstimated,0,(T3   * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,5,QtyEstimated,0,(T4   * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,6,QtyEstimated,0,(T5   * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,7,QtyEstimated,0,(T6   * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,8,QtyEstimated,0,(T7   * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,9,QtyEstimated,0,(T8   * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,10,QtyEstimated,0,(T9  * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,11,QtyEstimated,0,(T10 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,12,QtyEstimated,0,(T11 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,13,QtyEstimated,0,(T12 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,14,QtyEstimated,0,(T13 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,15,QtyEstimated,0,(T14 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,16,QtyEstimated,0,(T15 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,17,QtyEstimated,0,(T16 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,18,QtyEstimated,0,(T17 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,19,QtyEstimated,0,(T18 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,20,QtyEstimated,0,(T19 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,21,QtyEstimated,0,(T20 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,22,QtyEstimated,0,(T21 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,23,QtyEstimated,0,(T22 * (SerialWeight / 100)),'root','root',0),
              (CustomerId,LocationId,ContractId,ConsDay,24,QtyEstimated,0,(T23 * (SerialWeight / 100)),'root','root',0);

         END IF;
      UNTIL bDone END REPEAT;
  END;
  CLOSE curs;



  OPEN pods_cursor;
  BEGIN

        DECLARE bDone INT;
        DECLARE CONTINUE HANDLER FOR NOT FOUND SET bDone = 1;  

      SET bDone = 0;
      REPEAT
        FETCH pods_cursor INTO POD, QtyMeasured; 
        IF bDone = 0 THEN 

           INSERT INTO tblResultsErrors VALUES 
           (LocationCode, Quantity);

        END IF;

      UNTIL bDone END REPEAT;

  END;
  CLOSE pods_cursor;  

  IF NOT EXISTS ( SELECT * FROM tblResultsErrors ) THEN  
        BEGIN
            DELETE FROM EnergyIbdRecord WHERE Date BETWEEN MTH AND LAST_DAY(MTH);

            OPEN result;
            BEGIN

              DECLARE bDone INT;
              DECLARE CONTINUE HANDLER FOR NOT FOUND SET bDone = 1;  

              SET bDone = 0;
              REPEAT
                FETCH result INTO rCustomerId,rLocationId,rContractId,rDate,rTime,rQtyEstimated,rQtyPredicted,rQtyMeasured,rCreateUser,rUpdateUser,rFirmaId; 
                IF bDone = 0 THEN 

                    INSERT INTO EnergyIbdRecord (`CustomerId`, `LocationId`, `ContractId`, `Date`, `Time`, `QtyEstimated`, `QtyPredicted`, `QtyMeasured`, `CreateUser`, `UpdateUser`, `FirmaId`) 
                    VALUES (rCustomerId,rLocationId,rContractId,rDate,rTime,rQtyEstimated,rQtyPredicted,rQtyMeasured,rCreateUser,rUpdateUser,rFirmaId);

                END IF;

              UNTIL bDone END REPEAT;

            END;
            CLOSE result;
        END;
  ELSE 
        BEGIN
            SELECT * FROM tblResultsErrors;
        END;
  END IF;


END

Any suggestion to get rid of inserting what tblResults contains? Maybe there is necessary to run 2 separated procedures? Would be this an approach?

Answer 1

Wherever possible, avoid using CURSORs. SQL is designed to do things in bulk, not one row at a time.

Study constructs like

INSERT INTO ... SELECT ...;

CREATE TABLE ... SELECT ...;

For example, pods_cursor can probably be eliminated via:

INSERT INTO tblResultsErrors
        (POD, QtyMeasured)
    SELECT els.LocationCode, els.Quantity 
        FROM EnergyLocation el 
        RIGHT JOIN EnergyLocationSeries els
          ON els.LocationCode = el.Code2 OR els.LocationCode = el.Codep 
        LEFT JOIN EnergyContract ec
          on ec.LocationId = el.Id 
        WHERE el.Code2 IS NULL; 

(Ouch. Mixing RIGHT and LEFT makes my head spin like an owl's.)

Using OR in ON sounds very inefficient. What is the intent?