Mysql 存储过程 - 空间函数

Question

我想使用存储过程更新 mysql table 列。该列的数据类型为多边形（空间数据）

SET boundryData = (SELECT boundry FROM tbl_data WHERE tbl_id = currentRow);
SET updatedBoundry = ST_GeomFromText(boundryData);

给出并错误说提供给函数的数据无效，如果我硬编码相同的数据集如下，存储过程按预期工作

SET updatedBoundry  = ST_GeomFromText('POLYGON((6.546269854000059 80.15311213900003,6.54627481600005 80.15298415800004,6.546251038000038 80.15310380500006,6.546269854000059 80.15311213900003))');

整个存储过程如下

CREATE DEFINER=`root`@`localhost` PROCEDURE `new_procedure`()
BEGIN
    DECLARE rowCount INT;
    DECLARE boundryData longtext;
    DECLARE currentRow INT;
    DECLARE updatedBoundry polygon;

    SET rowCount=(SELECT COUNT(*) FROM tbl_kml_data);
    SET currentRow = 1;
    myUpdateLoop: WHILE (currentRow <= rowCount) DO
        SET @boundryData = (SELECT boundry FROM tbl_kml_data WHERE tbl_id = currentRow);
        SET updatedBoundry  =ST_GeomFromText('POLYGON((6.546269854000059 80.15311213900003,6.54627481600005 80.15298415800004,6.54605968900006 80.15315188800008,6.546251038000038 80.15310380500006,6.546269854000059 80.15311213900003))');        
        /*SET @updatedBoundry = ST_GeomFromText( @boundryData);*/

        UPDATE tbl_kml_data SET f_polygon = ST_GeomFromText(@boundryData) WHERE tbl_id = currentRow;

        SET currentRow = currentRow + 1;
    End WHILE myUpdateLoop;

END

知道如何解决这个问题

Answer 1

您真的需要存储过程来更新 table 吗？。一个简单的更新就可以完成这项工作：

UPDATE `tbl_kml_data`
SET `f_polygon` = `boundry`;

参见 dbfiddle。

如果你真的需要使用存储过程，你可以这样做：

DELIMITER //

DROP PROCEDURE IF EXISTS `new_procedure`//

CREATE PROCEDURE `new_procedure`()
BEGIN
  DECLARE `rowCount`, `currentRow` BIGINT UNSIGNED;
  DECLARE `boundryData` LONGTEXT;
  DECLARE `updatedBoundry` POLYGON;

  SET `rowCount` := (
    SELECT COUNT(*)
    FROM `tbl_kml_data`
  );
  SET `currentRow` := 1;

  `myUpdateLoop`: WHILE (`currentRow` <= `rowCount`) DO
    SET `boundryData` := (
      SELECT ST_AsText(`boundry`)
      FROM `tbl_kml_data`
      WHERE `tbl_id` = `currentRow`
    );
    -- SET `updatedBoundry` := ST_GeomFromText('POLYGON((6.546269854000059 80.15311213900003,6.54627481600005 80.15298415800004,6.54605968900006 80.15315188800008,6.546251038000038 80.15310380500006,6.546269854000059 80.15311213900003))');
    -- SET `updatedBoundry` := ST_GeomFromText(`boundryData`);

    UPDATE `tbl_kml_data`
    SET `f_polygon` = ST_GeomFromText(`boundryData`)
    WHERE `tbl_id` = `currentRow`;

    SET `currentRow` = `currentRow` + 1;
  END WHILE `myUpdateLoop`;
END//

DELIMITER ;

参见 dbfiddle。

重要的是要指出 9.4 User-Defined Variables and routine variables 13.1.17 CREATE PROCEDURE and CREATE FUNCTION Syntax 之间的区别，是不同的变量 (@boundryData != boundryData)。

Mysql 存储过程 - 空间函数

Mysql Stored Procedure - Spatial functions

mysql

gis

stored-procedures

spatial