How can I combine two procedures in one to populate one table rather than each of the two procedures populating it's own table?

Question

I created two tables that were each populated with a different procedure in MySQL with Sequel Pro. While each table has the correct information in it after running the respective procedure, I'm thinking that my data will be less scattered tables if I consolidate some of the tables more.

So, what I would like to do is combine the data from both tables into one. Below is the code I used to try to accomplish this. Unfortunately, it didn't work, and any help with the code would be much appreciated.

create table code:

-- Table: ip_ER_ERA_subtotal

-- DROP TABLE ip_ER_ERA_subtotal;

CREATE TABLE ip_ER_ERA_subtotal
(
  Starting_Pitcher VARCHAR(8) NOT NULL,
  Game_Date VARCHAR (10) NOT NULL,
  Game_Number VARCHAR (1) NOT NULL,
  innings_pitched double,
  ER double,
  ip_total double DEFAULT '0.0',
  ER_total double DEFAULT '0.0',
  ERA double DEFAULT '0.0',
  CONSTRAINT ip_ER_ERA_subtotal_pk 
      PRIMARY KEY (Starting_Pitcher, Game_Date , Game_Number)
) ENGINE=InnoDB

procedure code:

DELIMITER $$

    CREATE PROCEDURE accumulate_IP_ER()
    BEGIN
        DECLARE pit_id CHAR(10);
        DECLARE gdate DATE;
        DECLARE seq INT;
        DECLARE in_pit REAL;
        DECLARE earned_runs REAL;
        DECLARE accum REAL;
        DECLARE prev_year YEAR(4);
        DECLARE end_of_cursor BOOLEAN;

        DECLARE c1 CURSOR FOR
            SELECT Starting_Pitcher, Game_Date, Game_Number, innings_pitched
                FROM ip_ER_subtotal
                ORDER BY Starting_Pitcher, Game_Date, Game_Number;

        DECLARE CONTINUE HANDLER FOR NOT FOUND
            SET end_of_cursor := TRUE;

        TRUNCATE TABLE ip_ER_subtotal;
        INSERT INTO ip_ER_subtotal
            SELECT Starting_Pitcher, Game_Date, Game_Number, innings_pitched, 0.0
                FROM starting_pitchers_game_log;

        SET prev_year := 0;
        OPEN c1;

        fetch_loop: LOOP
            FETCH c1 INTO pit_id, gdate, seq, in_pit;
            IF end_of_cursor THEN
                LEAVE fetch_loop;
            END IF;
            IF YEAR(gdate) != prev_year THEN
                SET accum := 0.0;
                SET prev_year := YEAR(gdate);
            END IF;
            SET accum := accum + in_pit;
            UPDATE ip_ER_subtotal
                SET ip_total = accum
                WHERE Starting_Pitcher = pit_id
                  AND Game_Date = gdate
                  AND Game_Number = seq;
        END LOOP;
        CLOSE c1;

        DECLARE c2 CURSOR FOR
            SELECT Starting_Pitcher, Game_Date, Game_Number, earned_runs
                FROM ip_ER_subtotal
                ORDER BY Starting_Pitcher, Game_Date, Game_Number;

        DECLARE CONTINUE HANDLER FOR NOT FOUND
            SET end_of_cursor := TRUE;

        TRUNCATE TABLE ER_subtotal;
        INSERT INTO ip_ER_subtotal
            SELECT Starting_Pitcher, Game_Date, Game_Number, ER, 0.0
                FROM starting_pitchers_game_log;

        SET prev_year := 0;
        OPEN c2;

        fetch_loop: LOOP
            FETCH c2 INTO pit_id, gdate, seq, earned_runs;
            IF end_of_cursor THEN
                LEAVE fetch_loop;
            END IF;
            IF YEAR(gdate) != prev_year THEN
                SET accum := 0.0;
                SET prev_year := YEAR(gdate);
            END IF;
            SET accum := accum + earned_runs;
            UPDATE ip_ER_subtotal
                SET ER_total = accum
                WHERE Starting_Pitcher = pit_id
                  AND Game_Date = gdate
                  AND Game_Number = seq;
        END LOOP;
        CLOSE c2;                    
    END

I get the following error:

 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DECLARE c2 CURSOR FOR
            SELECT Starting_Pitcher, Game_Date, Game_Number, e' at line 46

Here is a screenshot of the first table I already created "ip_subtotal"

Here is a screenshot of the second table I already created "ER_subtotal"

Update:

Here is essentially your same code that I made minor changes to:

DELIMITER $$
CREATE PROCEDURE accumulate_IP_ER_ERA()
  BEGIN
    DECLARE pit_id VARCHAR(8);
    DECLARE gdate VARCHAR(10);
    DECLARE seq VARCHAR(1);
    DECLARE in_pit REAL;
    DECLARE earned_runs INT;
    DECLARE accum_ip REAL;
    DECLARE accum_er INT;
    DECLARE earned_run_avg REAL;
    DECLARE prev_year YEAR(4);
    DECLARE end_of_cursor BOOLEAN;

    DECLARE c1 CURSOR FOR
      SELECT Starting_Pitcher, Game_Date, Game_Number, innings_pitched, ER
        FROM ip_ER_ERA_subtotal
        ORDER BY Starting_Pitcher, Game_Date, Game_Number;

    DECLARE CONTINUE HANDLER FOR NOT FOUND
      SET end_of_cursor := TRUE;

    TRUNCATE TABLE ip_ER_ERA_subtotal;
    INSERT INTO ip_ER_ERA_subtotal
        (Starting_Pitcher, Game_Date, Game_Number, innings_pitched, ER)
      SELECT Starting_Pitcher, Game_Date, Game_Number, innings_pitched, ER
        FROM starting_pitcher_game_log;

    SET end_of_cursor := FALSE;
    SET prev_year := 0;
    OPEN c1;

    fetch_loop: LOOP
      FETCH c1 INTO pit_id, gdate, seq, in_pit, earned_runs, accum_ip, accum_er, earned_run_avg;
      IF end_of_cursor THEN
        LEAVE fetch_loop;
      END IF;
      IF YEAR(gdate) != prev_year THEN
        SET accum_ip := 0.0;
        SET accum_er := 0;
        SET prev_year := YEAR(gdate);
      END IF;
      SET accum_ip := accum_ip + in_pit;
      SET accum_er := accum_er + ER;
      SET earned_run_avg := (accum_er / accum_ip) * 9;
      UPDATE ip_ER_ERA_subtotal
        SET ip_total = accum_ip,
            ER_total = accum_er,
            STD_ERA = earned_run_avg
          WHERE Starting_Pitcher = pit_id
            AND Game_Date = gdate
            AND Game_Number = seq
            AND prev_year=YEAR;
    END LOOP;
    CLOSE c1;
  END

Here's the error:

Incorrect number of FETCH variables

I did try to see what if any variables aren't being fetched and tried to add "accum_ip", "accum_er", "earned_run_avg" but it didn't work...It seems like the eight variables are the ones that the latter three + ones in your fetch statement should be the ones needed...

Here's the table code:

-- Table: ip_ER_ERA_subtotal

-- DROP TABLE ip_ER_ERA_subtotal;

CREATE TABLE ip_ER_ERA_subtotal
(
  Starting_Pitcher VARCHAR(8) NOT NULL,
  Game_Date VARCHAR(10) NOT NULL,
  Game_Number INT(1) NOT NULL,
  innings_pitched double,
  ER double,
  ip_total double DEFAULT '0.0',
  ER_total double DEFAULT '0',
  STD_ERA double DEFAULT '0.0',
  CONSTRAINT ip_ER_ERA_subtotal_pk 
      PRIMARY KEY (Starting_Pitcher, Game_Date , Game_Number)
) ENGINE=InnoDB

update:

Here's the code based on your changes, but columns ER, ER_total, and STD_ERA are filled with only "Null" values.

DELIMITER $$

CREATE PROCEDURE accumulate_ip_ER_ERA()
BEGIN
    DECLARE pit_id VARCHAR(8);
    DECLARE gdate VARCHAR(10);
    DECLARE seq VARCHAR(1);
    DECLARE in_pit REAL;
    DECLARE ER REAL;
    DECLARE accum_ip REAL;
    DECLARE accum_er REAL;
    DECLARE earned_run_avg REAL;
    DECLARE prev_year YEAR(4);
    DECLARE end_of_cursor BOOLEAN;

    DECLARE c1 CURSOR FOR
      SELECT Starting_Pitcher, Game_Date, Game_Number, innings_pitched, ER
        FROM ip_ER_ERA_subtotal
        ORDER BY Starting_Pitcher, Game_Date, Game_Number;

    DECLARE CONTINUE HANDLER FOR NOT FOUND
      SET end_of_cursor := TRUE;

    TRUNCATE TABLE ip_ER_ERA_subtotal;
    INSERT INTO ip_ER_ERA_subtotal
        (Starting_Pitcher, Game_Date, Game_Number, innings_pitched, ER)
      SELECT Starting_Pitcher, Game_Date, Game_Number, innings_pitched, ER
        FROM starting_pitcher_game_log;

    SET end_of_cursor := FALSE;
    SET prev_year := 0;
    OPEN c1;

    fetch_loop: LOOP
      FETCH c1 INTO pit_id, gdate, seq, in_pit, ER;
      IF end_of_cursor THEN
        LEAVE fetch_loop;
      END IF;
      IF YEAR(gdate) != prev_year THEN
        SET accum_ip := 0.0;
        SET accum_er := 0.0;
        SET prev_year := YEAR(gdate);
      END IF;
      SET accum_ip := accum_ip + in_pit;
      SET accum_er := accum_er + ER;
      SET earned_run_avg := (accum_er / accum_ip) * 9;
      UPDATE ip_ER_ERA_subtotal
        SET ip_total = accum_ip,
            ER_total = accum_er,
            STD_ERA = earned_run_avg
          WHERE Starting_Pitcher = pit_id
            AND Game_Date = gdate
            AND Game_Number = seq;
    END LOOP;
    CLOSE c1;
  END
  $$

Here's a screenshot of the table:

Could it be that only a single formula can be handled in any given cursor operation?

SET accum_ip := accum_ip + in_pit;
  SET accum_er := accum_er + ER;
  SET earned_run_avg := (accum_er / accum_ip) * 9

Thank you for your help.

Darwin, Ok, here is the edited code that populates the following columns with correct values: Starting_Pitcher, Game_Date, Game_Number, innings pitched and ER from the table ip_ER_ERA_subtotal. Columns ER_total and STD_ERA have all "0"s in them.
Here is the code:

    DELIMITER $$
CREATE PROCEDURE accumulate_ip_ER_ERA()
    BEGIN
        DECLARE pit_id VARCHAR(8);
        DECLARE gdate VARCHAR(10);
        DECLARE seq VARCHAR(1);
        DECLARE in_pit REAL;
        DECLARE earned_runs REAL;
        DECLARE accum_ip REAL;
        DECLARE accum_er REAL;
        DECLARE earned_run_avg REAL;
        DECLARE prev_year YEAR(4);
        DECLARE end_of_cursor BOOLEAN;

        DECLARE c1 CURSOR FOR
          SELECT Starting_Pitcher, Game_Date, Game_Number, innings_pitched, ER
            FROM ip_ER_ERA_subtotal
            ORDER BY Starting_Pitcher, Game_Date, Game_Number;

        DECLARE CONTINUE HANDLER FOR NOT FOUND
          SET end_of_cursor := TRUE;

        TRUNCATE TABLE ip_ER_ERA_subtotal;
        INSERT INTO ip_ER_ERA_subtotal
            (Starting_Pitcher, Game_Date, Game_Number, innings_pitched, ER)
          SELECT Starting_Pitcher, Game_Date, Game_Number, innings_pitched, ER
            FROM starting_pitcher_game_log;

        SET end_of_cursor := FALSE;
        SET prev_year := 0;
        OPEN c1;

        fetch_loop: LOOP
          FETCH c1 INTO pit_id, gdate, seq, in_pit, earned_runs;
          IF end_of_cursor THEN
            LEAVE fetch_loop;
          END IF;
          IF YEAR(gdate) != prev_year THEN
            SET accum_ip := 0.0;
            SET accum_er := 0.0;
            SET earned_run_avg := 0.0;
            SET prev_year := YEAR(gdate);
          END IF;
          SET accum_ip := accum_ip + in_pit;
          SET accum_er := accum_er + ER;
          SET earned_run_avg := (accum_er / accum_ip) * 9;
          UPDATE ip_ER_ERA_subtotal
            SET ip_total = accum_ip,
                ER_total = accum_er,
                STD_ERA = earned_run_avg
              WHERE Starting_Pitcher = pit_id
                AND ER = earned_runs
                AND Game_Date = gdate
                AND Game_Number = seq;
        END LOOP;
        CLOSE c1;
      END
$$

I get the following error:

Unknown column 'ER' in 'field list'

Here is the screenshot of the table:

Now the "ER" column populated but no more "ip_total"

Ok, it finally worked with the below code. Not sure, but I had a hunch that it wasn't liking the name of the field "ER" from the table we were calling up the values (starting_pitcher_game_log) to be inserted into the new table. Don't know why it didn't like it...

EDIT: Here's my edited code to handle "NULL" and divide-by-zero situations:

DELIMITER $$

CREATE PROCEDURE accumulate_ip_ER_ERA()
BEGIN
        DECLARE pit_id VARCHAR(8);
        DECLARE gdate DATE;
        DECLARE seq INT;
        DECLARE in_pit REAL;
        DECLARE ER_id REAL;
        DECLARE accum_ip REAL;
        DECLARE accum_er REAL;
        DECLARE earned_run_avg REAL;
        DECLARE prev_year YEAR(4);
        DECLARE end_of_cursor BOOLEAN;

        DECLARE c1 CURSOR FOR
          SELECT Starting_Pitcher, Game_Date, Game_Number, innings_pitched, earned_runs
            FROM ip_ER_ERA_subtotal
            ORDER BY Starting_Pitcher, Game_Date, Game_Number;

        DECLARE CONTINUE HANDLER FOR NOT FOUND
          SET end_of_cursor := TRUE;

        TRUNCATE TABLE ip_ER_ERA_subtotal;
        INSERT INTO ip_ER_ERA_subtotal (Starting_Pitcher, Game_Date, Game_Number, innings_pitched, earned_runs)
        SELECT Starting_Pitcher, Game_Date, Game_Number, innings_pitched, earned_runs,
          IFNULL(innings_pitched, 0),  -- replace NULL with 0, if
          IFNULL(earned_runs, 0)              --   column not initialized
            FROM starting_pitcher_game_log;
        END IF;
        SET end_of_cursor := FALSE;
        SET prev_year := 0;
        OPEN c1;

        fetch_loop: LOOP
          FETCH c1 INTO pit_id, gdate, seq, in_pit, ER_id;
          IF end_of_cursor THEN
            LEAVE fetch_loop;
          END IF;
          IF YEAR(gdate) != prev_year THEN
            SET accum_ip := 0.0;
            SET accum_er := 0;
            SET earned_run_avg := 0.0;
            SET prev_year := YEAR(gdate);
          END IF;
          SET accum_ip := accum_ip + in_pit;
          SET accum_er := accum_er + ER_id;
          IF accum_er = 0 THEN  -- prevent divide-by-zero
        SET earned_run_avg := 0;
      ELSE          
          SET earned_run_avg := (accum_er / accum_ip) * 9;
          END IF;
            UPDATE ip_ER_ERA_subtotal
            SET ip_total = accum_ip,
                ER_total = accum_er,
                STD_ERA = earned_run_avg
              WHERE Starting_Pitcher = pit_id
                AND Game_Date = gdate
                AND Game_Number = seq;
        END LOOP;
        CLOSE c1;
      END

      $$

error:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(innings_pitched, 0), -- replace NULL with 0, if IFNULL(earned_runs, ' at line 25

UPDATE: Screenshots of table when sorting by STD_ERA showing abnormally high STD_ERA values at one end of the range for that field or grayed-out "NULL" values at the other end of the range.

Answer 1

Right; let's see what we have here.

First, the code has to be blocked as follows:

variable declarations
cursor declarations
handler declarations
everything else

So your DECLARE CURSOR c2 must appear between DECLARE CURSOR c1 and DECLARE CONTINUE HANDLER. Also, you only need one CONTINUE HANDLER because it takes effect from the point of declaration to the end of the procedure.

Next is the statement

INSERT INTO ip_ER_subtotal
    SELECT Starting_Pitcher, Game_Date, Game_Number, innings_pitched, 0.0
        FROM starting_pitchers_game_log;

The named columns in the SELECT clause are the columns you're selecting from, not the ones you're inserting into, so they have to be columns in the table starting_pitchers_game_log. Also, since the columns not being copied from starting_pitchers_game_log (that is, ip_total, er_total and era) all have default values, you could use a column list on the INSERT statement, like so:

INSERT INTO pitcher_stats_temp
    (Starting_Pitcher, Game_Date, Game_Number, innings_pitched, er)
  SELECT pitcher_id, game_date, game_seq, innings_pitched, runs
    FROM starting_pitchers_game_log;

This saves typing, documents which columns you're actually inserting values into and insulates your INSERT statement from the physical order of columns in the source and target tables.

Next, once you finish the CURSOR c1 loop, don't truncate the table or you'll lose all the work you've just done! TRUNCATE TABLE deletes all rows currently in the table, and is used here to clear out the results of the previous run.

Finally, the two loops have to have different labels, say fetch_loop_1 and fetch_loop_2. You would also need to reset accum and end_of_cursor before entering the second loop. However, in this case I believe we can do everything in one loop with one cursor, which makes the code simpler and thus easier to maintain.

Here's the complete procedure:

DROP PROCEDURE IF EXISTS pitcher_stats_era;

DELIMITER $$

CREATE PROCEDURE pitcher_stats_era()
  BEGIN
    DECLARE pit_id CHAR(10);
    DECLARE gdate DATE;
    DECLARE seq INT;
    DECLARE in_pit REAL;
    DECLARE er INT;
    DECLARE accum_ip REAL;
    DECLARE accum_er INT;
    DECLARE earned_run_avg REAL;
    DECLARE prev_year YEAR(4);
    DECLARE end_of_cursor BOOLEAN;

    DECLARE no_table CONDITION FOR SQLSTATE '42S02';

    DECLARE c1 CURSOR FOR
      SELECT pitcher_id, game_date, game_seq, innings_pitched, earned_runs
        FROM pitcher_stats_temp
        ORDER BY pitcher_id, game_date, game_seq;

    DECLARE CONTINUE HANDLER FOR NOT FOUND
      SET end_of_cursor := TRUE;

    DECLARE EXIT HANDLER FOR no_table
    BEGIN
      SIGNAL no_table
        SET MESSAGE_TEXT = "Work table not initialized. Please call pitcher_stats_reset() before continuing",
        MYSQL_ERRNO = 1146;
    END;
------------------------------------------------------------------
-- The following steps are now performed by pitcher_stats_reset()
------------------------------------------------------------------
--  TRUNCATE TABLE ip_subtotal;  -- Clear our work table for a new run
    -- Copy data from main table into work table
--  INSERT INTO ip_subtotal
--      (pitcher_id, game_date, game_seq, innings_pitched, earned_runs)
--    SELECT pitcher_id, game_date, game_seq,
--        IFNULL(innings_pitched, 0),  -- replace NULL with 0, if
--        IFNULL(runs, 0)              --   column not initialized
--      FROM starting_pitchers_game_log;
---------------------------------------------------------------------

    SET end_of_cursor := FALSE;  -- reset
    SET prev_year := 0;          -- reset control-break

    OPEN c1;

    fetch_loop: LOOP
      FETCH c1 INTO pit_id, gdate, seq, in_pit, er;
      IF end_of_cursor THEN
        LEAVE fetch_loop;
      END IF;

      -- check control-break conditions
      IF YEAR(gdate) != prev_year THEN
        SET accum_ip := 0.0;
        SET accum_er := 0;
        SET prev_year := YEAR(gdate);
      END IF;

      SET accum_ip := accum_ip + in_pit;
      SET accum_er := accum_er + er;
      IF accum_er = 0 THEN  -- prevent divide-by-zero
        SET earned_run_avg := 0;
      ELSE
        SET earned_run_avg := (accum_ip / accum_er) * 9;
      END IF;

      UPDATE pitcher_stats_temp
        SET ip_total = accum_ip,
            er_total = accum_er,
            std_era = earned_run_avg
        WHERE pitcher_id = pit_id
          AND game_date = gdate
          AND game_seq = seq;

    END LOOP;

    CLOSE c1;
  END
$$
DELIMITER ;

That should do the job. If anyone finds a bug, by all means please point it out.

EDIT: I've just added some code to illustrate how to protect against nulls coming from the source table, and how to avoid a divide-by-zero on the ERA calculation.

EDIT: I've changed back to my original column and table names in order to reduce my own confusion.

EDIT: Code changed to be consistent with the answer to How can I add a column to a work table using a new stored procedure