データの削除

Javaでは、例は次のとおりです。

// ds is an entity of com.mysql.cj.jdbc.MysqlDataSource

try (Connection connection = ds.getConnection()) {
    String sql = "DELETE FROM `bookshop`.`ratings` WHERE `rated_at` >= ? AND `rated_at` <= ?";
    PreparedStatement preparedStatement = connection.prepareStatement(sql);
    Calendar calendar = Calendar.getInstance();
    calendar.set(Calendar.MILLISECOND, 0);

    calendar.set(2022, Calendar.APRIL, 15, 0, 0, 0);
    preparedStatement.setTimestamp(1, new Timestamp(calendar.getTimeInMillis()));

    calendar.set(2022, Calendar.APRIL, 15, 0, 15, 0);
    preparedStatement.setTimestamp(2, new Timestamp(calendar.getTimeInMillis()));

    preparedStatement.executeUpdate();
} catch (SQLException e) {
    e.printStackTrace();
}

Golangでは、例は次のとおりです。

package main

import (
    "database/sql"
    "fmt"
    "time"

    _ "github.com/go-sql-driver/mysql"
)

func main() {
    db, err := sql.Open("mysql", "root:@tcp(127.0.0.1:4000)/bookshop")
    if err != nil {
        panic(err)
    }
    defer db.Close()

    startTime := time.Date(2022, 04, 15, 0, 0, 0, 0, time.UTC)
    endTime := time.Date(2022, 04, 15, 0, 15, 0, 0, time.UTC)

    bulkUpdateSql := fmt.Sprintf("DELETE FROM `bookshop`.`ratings` WHERE `rated_at` >= ? AND `rated_at` <= ?")
    result, err := db.Exec(bulkUpdateSql, startTime, endTime)
    if err != nil {
        panic(err)
    }
    _, err = result.RowsAffected()
    if err != nil {
        panic(err)
    }
}

Python では、例は次のとおりです。

import MySQLdb
import datetime
import time
connection = MySQLdb.connect(
    host="127.0.0.1",
    port=4000,
    user="root",
    password="",
    database="bookshop",
    autocommit=True
)
with connection:
    with connection.cursor() as cursor:
        start_time = datetime.datetime(2022, 4, 15)
        end_time = datetime.datetime(2022, 4, 15, 0, 15)
        delete_sql = "DELETE FROM `bookshop`.`ratings` WHERE `rated_at` >= %s AND `rated_at` <= %s"
        affect_rows = cursor.execute(delete_sql, (start_time, end_time))
        print(f'delete {affect_rows} data')

Golangでは、一括削除の例は次のとおりです。

package main

import (
    "database/sql"
    "fmt"
    "time"

    _ "github.com/go-sql-driver/mysql"
)

func main() {
    db, err := sql.Open("mysql", "root:@tcp(127.0.0.1:4000)/bookshop")
    if err != nil {
        panic(err)
    }
    defer db.Close()

    affectedRows := int64(-1)
    startTime := time.Date(2022, 04, 15, 0, 0, 0, 0, time.UTC)
    endTime := time.Date(2022, 04, 15, 0, 15, 0, 0, time.UTC)

    for affectedRows != 0 {
        affectedRows, err = deleteBatch(db, startTime, endTime)
        if err != nil {
            panic(err)
        }
    }
}

// deleteBatch delete at most 1000 lines per batch
func deleteBatch(db *sql.DB, startTime, endTime time.Time) (int64, error) {
    bulkUpdateSql := fmt.Sprintf("DELETE FROM `bookshop`.`ratings` WHERE `rated_at` >= ? AND `rated_at` <= ? LIMIT 1000")
    result, err := db.Exec(bulkUpdateSql, startTime, endTime)
    if err != nil {
        return -1, err
    }
    affectedRows, err := result.RowsAffected()
    if err != nil {
        return -1, err
    }

    fmt.Printf("delete %d data\n", affectedRows)
    return affectedRows, nil
}

各反復で、 DELETE 2022-04-15 00:00:00から2022-04-15 00:15:00までの最大 1000 行を削除します。

Python での一括削除の例は次のとおりです。

import MySQLdb
import datetime
import time
connection = MySQLdb.connect(
    host="127.0.0.1",
    port=4000,
    user="root",
    password="",
    database="bookshop",
    autocommit=True
)
with connection:
    with connection.cursor() as cursor:
        start_time = datetime.datetime(2022, 4, 15)
        end_time = datetime.datetime(2022, 4, 15, 0, 15)
        affect_rows = -1
        while affect_rows != 0:
            delete_sql = "DELETE FROM `bookshop`.`ratings` WHERE `rated_at` >= %s AND  `rated_at` <= %s LIMIT 1000"
            affect_rows = cursor.execute(delete_sql, (start_time, end_time))
            print(f'delete {affect_rows} data')
            time.sleep(1)

各反復で、 DELETE 2022-04-15 00:00:00から2022-04-15 00:15:00までの最大 1000 行を削除します。