帮助MySQL LOAD DATA INFILE(Help with MySQL LOAD DATA INFILE)

 我想加载一个如下所示的CSV文件： 
 
Acct. No.,1-15 Days,16-30 Days,31-60 Days,61-90 Days,91-120 Days,Beyond 120 Days
2314134101,898.89,8372.16,5584.23,7744.41,9846.54,2896.25
2414134128,5457.61,7488.26,9594.02,6234.78,273.7,2356.13
2513918869,2059.59,7578.59,9395.51,7159.15,5827.48,3041.62
1687950783,4846.85,8364.22,9892.55,7213.45,8815.33,7603.4
2764856043,5250.11,9946.49,8042.03,6058.64,9194.78,8296.2
2865446086,596.22,7670.04,8564.08,3263.85,9662.46,7027.22
,4725.99,1336.24,9356.03,1572.81,4942.11,6088.94
,8248.47,956.81,8713.06,2589.14,5316.68,1543.67
,538.22,1473.91,3292.09,6843.89,2687.07,9808.05
,9885.85,2730.72,6876,8024.47,1196.87,1655.29
 
 但是如果你注意到，有些字段是不完整的。 我想MySQL只会跳过缺少第一列的行。 当我运行命令时： 
 
LOAD DATA LOCAL INFILE 'test-long.csv' REPLACE INTO TABLE accounts
    FIELDS TERMINATED BY ',' LINES TERMINATED BY '\r\n'
    IGNORE 1 LINES
    (cf_535, cf_580, cf_568, cf_569, cf_571, cf_572);
 
 MySQL的输出是： 
 
Query OK, 41898 rows affected, 20948 warnings (0.78 sec)
Records: 20949  Deleted: 20949  Skipped: 0  Warnings: 20948
 
 行数仅为20,949，但MySQL报告为受影响的41,898行。 为什么这样？ 此外，表格中没有任何改变。 我也无法看到所产生的警告是什么。 我想使用LOAD DATA INFILE，因为它需要python半秒来更新每一行，对于一个包含20,000多条记录的文件，它会转换为2.77小时。 
 
 更新：修改代码以将自动提交设置为'False'并添加了db.commit（）语句： 
 
# Tell MySQLdb to turn off auto-commit
db.autocommit(False) 

# Set count to 1
count = 1
while count < len(contents):
    if contents[count][0] != '':
        cursor.execute("""
            UPDATE accounts SET cf_580 = %s, cf_568 = %s, cf_569 = %s, cf_571 = %s, cf_572 = %s
            WHERE cf_535 = %s""" % (contents[count][1], contents[count][2], contents[count][3], contents[count][4], contents[count][5], contents[count][0]))
    count += 1

try:
    db.commit()
except:
    db.rollback()

I want to load a CSV file that looks like this:
 
Acct. No.,1-15 Days,16-30 Days,31-60 Days,61-90 Days,91-120 Days,Beyond 120 Days
2314134101,898.89,8372.16,5584.23,7744.41,9846.54,2896.25
2414134128,5457.61,7488.26,9594.02,6234.78,273.7,2356.13
2513918869,2059.59,7578.59,9395.51,7159.15,5827.48,3041.62
1687950783,4846.85,8364.22,9892.55,7213.45,8815.33,7603.4
2764856043,5250.11,9946.49,8042.03,6058.64,9194.78,8296.2
2865446086,596.22,7670.04,8564.08,3263.85,9662.46,7027.22
,4725.99,1336.24,9356.03,1572.81,4942.11,6088.94
,8248.47,956.81,8713.06,2589.14,5316.68,1543.67
,538.22,1473.91,3292.09,6843.89,2687.07,9808.05
,9885.85,2730.72,6876,8024.47,1196.87,1655.29
 
But if you notice, some of the fields are incomplete. I'm thinking MySQL will just skip the row where the first column is missing. When I run the command:
 
LOAD DATA LOCAL INFILE 'test-long.csv' REPLACE INTO TABLE accounts
    FIELDS TERMINATED BY ',' LINES TERMINATED BY '\r\n'
    IGNORE 1 LINES
    (cf_535, cf_580, cf_568, cf_569, cf_571, cf_572);
 
And the MySQL output is:
 
Query OK, 41898 rows affected, 20948 warnings (0.78 sec)
Records: 20949  Deleted: 20949  Skipped: 0  Warnings: 20948
 
The number of lines is only 20,949 but MySQL reports it as 41,898 rows affected. Why so? Also, nothing really changed in the table. I also couldn't see what the warnings generated is all about. I wanted to use the LOAD DATA INFILE because it takes python half a second to update each row which translates to 2.77 hours for a file with 20,000+ records.
 
UPDATE: Modified the code to set auto-commit to 'False' and added a db.commit() statement:
 
# Tell MySQLdb to turn off auto-commit
db.autocommit(False) 

# Set count to 1
count = 1
while count < len(contents):
    if contents[count][0] != '':
        cursor.execute("""
            UPDATE accounts SET cf_580 = %s, cf_568 = %s, cf_569 = %s, cf_571 = %s, cf_572 = %s
            WHERE cf_535 = %s""" % (contents[count][1], contents[count][2], contents[count][3], contents[count][4], contents[count][5], contents[count][0]))
    count += 1

try:
    db.commit()
except:
    db.rollback()

原文：https://stackoverflow.com/questions/1236971