CSV字符串表存储过程

StoredProcedure的（在csvString VARCHAR（1000））CSV字符串表存储过程

csvString有1,2,3,4,5,6

我想这个CSV字符串转换成像表下面

Expected output

如果CSV串是1,2,3,4,5,6,7,8-然后

Expected output

在此先感谢

来源

2017-06-02 Aakash

如果您可以详细说明问题并将预期结果放在您的问题中（例如在代码格式化部分中），那么您应该先自己编写一些代码，然后询问何时卡住 - 请阅读[问]。 – Picard

你可以编写一个函数来分割字符串并返回奇数和偶数值并保存为可重复使用 –

验证，并根据需要调整：

mysql> SELECT VERSION(); 
+-----------+ 
| VERSION() | 
+-----------+ 
| 5.7.18 | 
+-----------+ 
1 row in set (0.00 sec) 

mysql> DROP PROCEDURE IF EXISTS `insert_split`; 
Query OK, 0 rows affected (0.00 sec) 

mysql> DROP FUNCTION IF EXISTS `split_str`; 
Query OK, 0 rows affected (0.00 sec) 

mysql> DROP TABLE IF EXISTS `tbl`; 
Query OK, 0 rows affected (0.00 sec) 

mysql> CREATE TABLE IF NOT EXISTS `tbl` (
    -> `col1` VARCHAR(255), 
    -> `col2` VARCHAR(255) 
    ->); 
Query OK, 0 rows affected (0.00 sec) 

mysql> -- MySQL Split String Function by Federico Cargnelutti 
mysql> -- http://blog.fedecarg.com/2009/02/22/mysql-split-string-function/ 
mysql> CREATE FUNCTION `split_str` (
    -> `str` TEXT, 
    -> `delim` CHAR(1), 
    -> `item` INT UNSIGNED 
    ->) RETURNS VARCHAR(255) 
    -> BEGIN 
    -> DECLARE `_current_str` TEXT DEFAULT SUBSTRING_INDEX(`str`, `delim`, `item`); 
    -> DECLARE `_prev_str` TEXT DEFAULT SUBSTRING_INDEX(`str`, `delim`, `item`-1); 
    -> IF `_current_str` = `_prev_str` THEN 
    ->  RETURN NULL; 
    -> ELSE 
    ->  RETURN REPLACE(
    ->  SUBSTRING(
    ->   `_current_str`, 
    ->   CHAR_LENGTH(`_prev_str`) + 1 
    ->  ), 
    ->  `delim`, ''); 
    -> END IF; 
    -> END// 
Query OK, 0 rows affected (0.00 sec) 

mysql> DELIMITER // 

mysql> CREATE PROCEDURE `insert_split`(`str` TEXT) 
    -> BEGIN 
    -> DECLARE `_delim` CHAR(1) DEFAULT ','; 
    -> DECLARE `_iteration` INT UNSIGNED DEFAULT 0; 
    -> DECLARE `_current_value` VARCHAR(255); 
    -> DECLARE `_odd_value` VARCHAR(255) DEFAULT ''; 
    -> `repeat`: LOOP 
    ->  SET `_iteration` := `_iteration` + 1; 
    ->  SET `_current_value` := `split_str`(`str`, `_delim`, `_iteration`); 
    ->  IF `_current_value` IS NULL THEN 
    ->  LEAVE `repeat`; 
    ->  END IF; 
    ->  IF (`_iteration` MOD 2) = 0 THEN 
    ->  INSERT INTO `tbl` (`col1`, `col2`) 
    ->  VALUES (NULLIF(`_odd_value`, ''), NULLIF(`_current_value`, '')); 
    ->  ELSE 
    ->  SET `_odd_value` := `_current_value`; 
    ->  END IF; 
    -> END LOOP `repeat`; 
    -> END// 
Query OK, 0 rows affected (0.00 sec) 

mysql> DELIMITER ; 

mysql> CALL `insert_split`('1,2,3,4,5,6'); 
Query OK, 1 row affected (0.00 sec) 

mysql> SELECT `col1`, `col2` 
    -> FROM `tbl`; 
+------+------+ 
| col1 | col2 | 
+------+------+ 
| 1 | 2 | 
| 3 | 4 | 
| 5 | 6 | 
+------+------+ 
3 rows in set (0.00 sec) 

mysql> TRUNCATE TABLE `tbl`; 
Query OK, 0 rows affected (0.00 sec) 

mysql> CALL `insert_split`('1,2,3,4,5,6,7,8'); 
Query OK, 1 row affected (0.00 sec) 

mysql> SELECT `col1`, `col2` 
    -> FROM `tbl`; 
+------+------+ 
| col1 | col2 | 
+------+------+ 
| 1 | 2 | 
| 3 | 4 | 
| 5 | 6 | 
| 7 | 8 | 
+------+------+ 
4 rows in set (0.00 sec)

见db-fiddle。

UPDATE

如果使用奇数和偶数值，可以使用以下命令：

mysql> SELECT VERSION(); 
+-----------+ 
| VERSION() | 
+-----------+ 
| 5.7.18 | 
+-----------+ 
1 row in set (0.00 sec) 

mysql> DROP PROCEDURE IF EXISTS `insert_split`; 
Query OK, 0 rows affected (0.00 sec) 

mysql> DROP FUNCTION IF EXISTS `split_str`; 
Query OK, 0 rows affected (0.00 sec) 

mysql> DROP TABLE IF EXISTS `tbl`; 
Query OK, 0 rows affected (0.00 sec) 

mysql> CREATE TABLE IF NOT EXISTS `tbl` (
    -> `col1` VARCHAR(255), 
    -> `col2` VARCHAR(255) 
    ->); 
Query OK, 0 rows affected (0.00 sec) 

mysql> DELIMITER // 

mysql> -- MySQL Split String Function by Federico Cargnelutti 
mysql> -- http://blog.fedecarg.com/2009/02/22/mysql-split-string-function/ 
mysql> CREATE FUNCTION `split_str` (
    -> `str` TEXT, 
    -> `delim` CHAR(1), 
    -> `item` INT UNSIGNED, 
    -> `max_len_str` SMALLINT UNSIGNED 
    ->) RETURNS VARCHAR(255) 
    -> BEGIN 
    -> DECLARE `_current_str` TEXT DEFAULT SUBSTRING_INDEX(`str`, `delim`, `item`); 
    -> DECLARE `_prev_str` TEXT DEFAULT SUBSTRING_INDEX(`str`, `delim`, `item`-1); 
    -> IF `_current_str` = `_prev_str` AND CHAR_LENGTH(`_prev_str`) = `max_len_str` THEN 
    ->  RETURN NULL; 
    -> ELSE 
    ->  RETURN REPLACE(
    ->  SUBSTRING(
    ->   `_current_str`, 
    ->   CHAR_LENGTH(`_prev_str`) + 1 
    ->  ), 
    ->  `delim`, ''); 
    -> END IF; 
    -> END// 
Query OK, 0 rows affected (0.00 sec) 

mysql> CREATE PROCEDURE `insert_split`(`str` TEXT) 
    -> BEGIN 
    -> DECLARE `_max_length_str` SMALLINT UNSIGNED DEFAULT CHAR_LENGTH(`str`); 
    -> DECLARE `_delim` CHAR(1) DEFAULT ','; 
    -> DECLARE `_iteration` INT UNSIGNED DEFAULT 0; 
    -> DECLARE `_odd_value`, `_even_value` VARCHAR(255); 
    -> `repeat`: LOOP 
    ->  SET `_odd_value` := `split_str`(`str`, `_delim`, `_iteration` + 1, `_max_length_str`); 
    ->  SET `_even_value` := `split_str`(`str`, `_delim`, `_iteration` + 2, `_max_length_str`); 
    ->  IF `_odd_value` IS NULL AND `_even_value` IS NULL THEN 
    ->  LEAVE `repeat`; 
    ->  END IF; 
    ->  INSERT INTO `tbl` (`col1`, `col2`) 
    ->  VALUES (NULLIF(`_odd_value`, ''), NULLIF(`_even_value`, '')); 
    ->  SET `_iteration` := `_iteration` + 2; 
    -> END LOOP `repeat`; 
    -> END// 
Query OK, 0 rows affected (0.00 sec) 

mysql> DELIMITER ; 

mysql> TRUNCATE TABLE `tbl`; 
Query OK, 0 rows affected (0.00 sec) 

mysql> CALL `insert_split`('1,2,3,4,5,6'); 
Query OK, 1 row affected (0.00 sec) 

mysql> SELECT `col1`, `col2` 
    -> FROM `tbl`; 
+------+------+ 
| col1 | col2 | 
+------+------+ 
| 1 | 2 | 
| 3 | 4 | 
| 5 | 6 | 
+------+------+ 
3 rows in set (0.00 sec) 

mysql> TRUNCATE TABLE `tbl`; 
Query OK, 0 rows affected (0.00 sec) 

mysql> CALL `insert_split`('1,2,3,4,5,6,7,8'); 
Query OK, 1 row affected (0.00 sec) 

mysql> SELECT `col1`, `col2` 
    -> FROM `tbl`; 
+------+------+ 
| col1 | col2 | 
+------+------+ 
| 1 | 2 | 
| 3 | 4 | 
| 5 | 6 | 
| 7 | 8 | 
+------+------+ 
4 rows in set (0.00 sec) 

mysql> TRUNCATE TABLE `tbl`; 
Query OK, 0 rows affected (0.01 sec) 

mysql> CALL `insert_split`(',,,'); 
Query OK, 1 row affected (0.00 sec) 

mysql> SELECT `col1`, `col2` 
    -> FROM `tbl`; 
+------+------+ 
| col1 | col2 | 
+------+------+ 
| NULL | NULL | 
| NULL | NULL | 
+------+------+ 
2 rows in set (0.00 sec) 

mysql> TRUNCATE TABLE `tbl`; 
Query OK, 0 rows affected (0.00 sec) 

mysql> CALL `insert_split`(',1,,,3'); 
Query OK, 1 row affected (0.00 sec) 

mysql> SELECT `col1`, `col2` 
    -> FROM `tbl`; 
+------+------+ 
| col1 | col2 | 
+------+------+ 
| NULL | 1 | 
| NULL | NULL | 
| 3 | NULL | 
+------+------+ 
3 rows in set (0.00 sec)

见db-fiddle。

来源

2017-06-02 12:56:16 wchiquito

It Works .. !!非常感谢。 – Aakash

根据我的要求，我将收到11个多重csv字符串。我需要将它插入11列。我虽然根据它改变逻辑。但看起来我们在这里使用偶数和奇数值。再次，它对我来说是11列逻辑的死胡同。无论如何，我可以得到你的帮助...在此先感谢... – Aakash

@Aakash：查看更新的答案。 – wchiquito

CSV字符串表存储过程

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