-- Remove the handshake VIN column from every physical charging-order shard.
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-- Execute directly on the backend MySQL instance, not through the database proxy.
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-- The procedure is idempotent: only tables that still own the column are altered.
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-- After this change all charging orders (CD/SD/VD) store the device-reported VIN in actual_vin only.
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USE `charging_pile_order`;
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DROP PROCEDURE IF EXISTS `drop_charging_order_vin`;
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DELIMITER $$
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CREATE PROCEDURE `drop_charging_order_vin`()
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BEGIN
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DECLARE shard_no INT DEFAULT 0;
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DECLARE target_table VARCHAR(64);
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DECLARE table_exists INT DEFAULT 0;
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DECLARE column_exists INT DEFAULT 0;
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WHILE shard_no < 50 DO
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SET target_table = CONCAT('t_charging_order_', shard_no);
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SELECT COUNT(*) INTO table_exists
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FROM information_schema.tables
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WHERE table_schema = DATABASE()
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AND table_name = target_table;
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SELECT COUNT(*) INTO column_exists
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FROM information_schema.columns
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WHERE table_schema = DATABASE()
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AND table_name = target_table
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AND column_name = 'vin';
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IF table_exists = 1 AND column_exists = 1 THEN
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SET @ddl = CONCAT('ALTER TABLE `', target_table, '` DROP COLUMN `vin`');
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PREPARE stmt FROM @ddl;
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EXECUTE stmt;
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DEALLOCATE PREPARE stmt;
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END IF;
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SET shard_no = shard_no + 1;
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END WHILE;
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END$$
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DELIMITER ;
|
|
CALL `drop_charging_order_vin`();
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DROP PROCEDURE `drop_charging_order_vin`;
|
|
SELECT COUNT(*) AS shard_count,
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SUM(CASE WHEN c.column_name = 'vin' THEN 1 ELSE 0 END) AS vin_column_count
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FROM information_schema.tables t
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LEFT JOIN information_schema.columns c
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ON c.table_schema = t.table_schema
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AND c.table_name = t.table_name
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AND c.column_name = 'vin'
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WHERE t.table_schema = DATABASE()
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AND t.table_name REGEXP '^t_charging_order_[0-9]+$';
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