Question

我有一个包含此字段的表格（型号，日期，价格，数量）我需要一个SQL（对MySQL），它给我一个动态表格，其中包含型号名称，数量和总销售额（价格*数量），但以月份（日期）分隔。例如。

            April           |         May          |     June
Model |quantity| Gross Sales|  quantity|Gross Sales| quantity | Gross Sales
  1       6         50           4        40           5            45
  2       10         30          3        9            5            15

谢谢！

更新：

表格：

    CREATE TABLE `sales` (
      `model` varchar DEFAULT NULL,
      `price` int DEFAULT NULL,
      `quantity` int(2) DEFAULT NULL,
      `date` timestamp
    )

Answer 1

这非常棘手，也许有更好的方法可以做到这一点，但这是我的两分钱，请注意在MySQL中分组的列名是不可能的，因为列和列名之间只有关系是1：1。

下面是一些代码，它生成测试数据，然后构建一个依赖于动态SQL的过程来生成返回所需结果所必需的查询，这也是动态执行的。请注意，代码应该运行时没有错误，但DROP语句被注释以防止对现有结构造成不必要的损坏。最终存储过程中不需要RANDBETWEEN程序，但用于生成测试数据。

#DROP TABLE IF EXISTS sales;

CREATE TABLE `sales` (
      `model` varchar(64) DEFAULT NULL,
      `price` int DEFAULT NULL,
      `quantity` int(2) DEFAULT NULL,
      `date` datetime
    );

SET @VMinModel := 1;
SET @VMaxModel := 5;

SET @VMinPrice := 10;
SET @VMaxPrice := 100;

SET @VMinQuantity := 1;
SET @VMaxQuantity := 10;

SET @VMinTime := UNIX_TIMESTAMP('2016-01-01');
SET @VMaxTime := UNIX_TIMESTAMP('2016-12-31');

#DROP FUNCTION RANDBETWEEN;

DELIMITER $

CREATE FUNCTION RANDBETWEEN(VMin INTEGER UNSIGNED, VMax INTEGER UNSIGNED) RETURNS INTEGER UNSIGNED
DETERMINISTIC
BEGIN

    RETURN ROUND(RAND() * (VMax - VMin) + VMin);

END$

DELIMITER ;

INSERT INTO `sales` SELECT RANDBETWEEN(@VMinModel, @VMaxModel), RANDBETWEEN(@VMinPrice, @VMaxPrice), RANDBETWEEN(@VMinQuantity, @VMaxQuantity), FROM_UNIXTIME(RANDBETWEEN(@VMinTime, @VMaxTime)) FROM information_schema.COLUMNS LIMIT 1000;

SET @VXDimension := 'model';
SET @VYDimension := 'DATE_FORMAT(date, ''%Y-%m'')';
SET @VMeasures := 'quantity, quantity * price';
SET @VTable := 'sales';

#DROP PROCEDURE IF EXISTS singleDimensionMeltAndCast;

DELIMITER $

CREATE PROCEDURE singleDimensionMeltAndCast (VXDimension CHAR(255), VYDimension CHAR(255), VMeasures CHAR(255), VTable CHAR(255)) 
BEGIN

    SET SESSION group_concat_max_len = 65536;

    DROP TEMPORARY TABLE IF EXISTS YDimensionValues;
    SET @VCreateYDimensionValueTable := CONCAT('CREATE TEMPORARY TABLE YDimensionValues SELECT DISTINCT ', VYDimension, ' AS YDim1 FROM ', VTable, ' ORDER BY ', VYDimension, ' ASC;');

    PREPARE stmt FROM @VCreateYDimensionValueTable;
    EXECUTE stmt;
    DEALLOCATE PREPARE stmt;

    DROP TEMPORARY TABLE IF EXISTS Measures;
    CREATE TEMPORARY TABLE Measures (measure CHAR(255));
    SET @VCreateMeasuresTable := CONCAT('INSERT INTO Measures VALUES(''', REPLACE(VMeasures, ', ', '''), ('''), ''')');

    PREPARE stmt FROM @VCreateMeasuresTable;
    EXECUTE stmt;
    DEALLOCATE PREPARE stmt;

    SET @VYDimensionSQLFieldsComponent = (SELECT GROUP_CONCAT('SUM(IF(', VYDimension, ' = ''', YDim1, ''', ', measure, ', 0)) `[', YDim1, ' x ',  measure, ']`' SEPARATOR ', ') FROM YDimensionValues, Measures WHERE TRUE);
    SET @VYDimensionSQLGroupComponent = (SELECT GROUP_CONCAT('IF(', VYDimension, ' = ''', YDim1, ''', ', measure, ', 0)' SEPARATOR ', ') FROM YDimensionValues, Measures WHERE TRUE);

    SET @VFinalQuery := CONCAT('SELECT ', VXDimension, ', ', @VYDimensionSQLFieldsComponent, ' FROM ', VTable, ' GROUP BY ', @VYDimensionSQLGroupComponent, ' ORDER BY ', VXDimension, ';');
    PREPARE stmt FROM @VFinalQuery;
    EXECUTE stmt;
    DEALLOCATE PREPARE stmt;

END$

DELIMITER ;

CALL singleDimensionMeltAndCast(@VXDimension, @VYDimension, @VMeasures, @VTable);

如果您有任何问题，请与我们联系。

此致

詹姆斯

MySQL按月转动数据

1 个答案: