MySQL temporary table

In MySQL, a temporary table is a special type of table that allows you to store a temporary result set, which you can reuse several times in a single session.

A temporary table is very handy when it is impossible or expensive to query data that requires a single SELECT statement with the JOIN clauses

Creating a MySQL temporary table

CREATE TEMPORARY TABLE temp_table LIKE update_table;

Using LOAD DATA INFILE

Your MySQL server has been started with --secure-file-priv option which basically limits from which directories you can load files using LOAD DATA INFILE.

The secure_file_priv variable is used to limit the effect of data import and export operations.

mysql> SHOW VARIABLES LIKE "secure_file_priv";
+------------------+-----------------------+
| Variable_name    | Value                 |
+------------------+-----------------------+
| secure_file_priv | /var/lib/mysql-files/ |
+------------------+-----------------------+
1 row in set (0.01 sec)

mysql>

• Move csv data file to the directory specified by secure-file-priv.

cp data.csv /var/lib/mysql-files/

• Load data

LOAD DATA INFILE '/var/lib/mysql-files/data.csv'
INTO TABLE temp_table
FIELDS TERMINATED BY ',' (name, update_column);

Update table

UPDATE update_table
INNER JOIN temp_table
ON temp_table.name = update_table.name  
SET update_table.update_column = temp_table.update_column;

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