32 строки
862 B
SQL
32 строки
862 B
SQL
SET @preparedStatement = (SELECT IF(
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(
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SELECT COUNT(*) FROM INFORMATION_SCHEMA.STATISTICS
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WHERE table_name = 'Threads'
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AND table_schema = DATABASE()
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AND index_name = 'idx_threads_channel_id'
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) > 0,
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'DROP INDEX idx_threads_channel_id ON Threads;',
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'SELECT 1'
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));
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PREPARE removeIndexIfExists FROM @preparedStatement;
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EXECUTE removeIndexIfExists;
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DEALLOCATE PREPARE removeIndexIfExists;
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SET @preparedStatement = (SELECT IF(
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(
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SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
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WHERE table_name = 'Threads'
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AND table_schema = DATABASE()
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AND column_name = 'ChannelId'
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) > 0,
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'ALTER TABLE Threads DROP COLUMN ChannelId;',
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'SELECT 1'
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));
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PREPARE alterIfExists FROM @preparedStatement;
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EXECUTE alterIfExists;
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DEALLOCATE PREPARE alterIfExists;
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DROP TABLE IF EXISTS Threads;
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