MySQL データベースにロードする必要がある CSV データがたくさんあります。まあ、おそらくCSVっぽい。（編集：実際には、RFC 4180 で説明されているもののように見えます）
各行は、コンマで区切られた二重引用符で囲まれた文字列のリストです。列の値に含まれる二重引用符をエスケープするには、二重引用符を使用します。バックスラッシュはそれ自体を表すことができます。
たとえば、次の行です。
"", "\wave\", ""hello,"" said the vicar", "what are ""scare-quotes"" good for?", "I'm reading ""Bossypants"""
JSON に解析された場合は次のようになります。
[ "", "\\wave\\", "\"hello,\" said the vicar", "what are \"scare-quotes\" good for?", "I'm reading \"Bossypants\"" ]
を使用して CSV を読み取ろうとしていますが、LOAD DATA奇妙な動作が発生しています。
例として、単純な 2 列のテーブルがあるとします。
shell% mysql exampledb -e "describe person"
+-------+-----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-----------+------+-----+---------+-------+
| ID | int(11) | YES | | NULL | |
| UID | char(255) | YES | | NULL | |
+-------+-----------+------+-----+---------+-------+
shell%
入力ファイルの最初の非ヘッダー行が次で終わる場合"":
shell% cat temp-1.csv
"ID","UID"
"9",""
"0","Steve the Pirate"
"1","\Alpha"
"2","Hoban ""Wash"" Washburne"
"3","Pastor Veal"
"4","Tucker"
"10",""
"5","Simon"
"6","Sonny"
"7","Wat\"
ヘッダー以外のすべての行をロードできますが、最初の行は次のとおりです。
mysql> DELETE FROM person;
Query OK, 0 rows affected (0.00 sec)
mysql> LOAD DATA
LOCAL INFILE 'temp-1.csv'
INTO TABLE person
FIELDS
TERMINATED BY ','
ENCLOSED BY '"'
ESCAPED BY '"'
LINES
TERMINATED BY '\n'
IGNORE 1 LINES
;
Query OK, 9 rows affected (0.00 sec)
Records: 9 Deleted: 0 Skipped: 0 Warnings: 0
mysql> SELECT * FROM person;
+------+------------------------+
| ID | UID |
+------+------------------------+
| 0 | Steve the Pirate |
| 10 | |
| 1 | \Alpha |
| 2 | Hoban "Wash" Washburne |
| 3 | Pastor Veal |
| 4 | Tucker |
| 5 | Simon |
| 6 | Sonny |
| 7 | Wat\ |
+------+------------------------+
9 rows in set (0.00 sec)
または、ヘッダーを含むすべての行をロードできます。
mysql> DELETE FROM person;
Query OK, 9 rows affected (0.00 sec)
mysql> LOAD DATA
LOCAL INFILE 'temp-1.csv'
INTO TABLE person
FIELDS
TERMINATED BY ','
ENCLOSED BY '"'
ESCAPED BY '"'
LINES
TERMINATED BY '\n'
IGNORE 0 LINES
;
Query OK, 11 rows affected, 1 warning (0.01 sec)
Records: 11 Deleted: 0 Skipped: 0 Warnings: 1
mysql> show warnings;
+---------+------+--------------------------------------------------------+
| Level | Code | Message |
+---------+------+--------------------------------------------------------+
| Warning | 1366 | Incorrect integer value: 'ID' for column 'ID' at row 1 |
+---------+------+--------------------------------------------------------+
1 row in set (0.00 sec)
mysql> SELECT * FROM person;
+------+------------------------+
| ID | UID |
+------+------------------------+
| 0 | UID |
| 9 | |
| 0 | Steve the Pirate |
| 10 | |
| 1 | \Alpha |
| 2 | Hoban "Wash" Washburne |
| 3 | Pastor Veal |
| 4 | Tucker |
| 5 | Simon |
| 6 | Sonny |
| 7 | Wat\ |
+------+------------------------+
11 rows in set (0.00 sec)
入力ファイルの行が で終わらない場合"":
shell% cat temp-2.csv
"ID","UID"
"0","Steve the Pirate"
"1","\Alpha"
"2","Hoban ""Wash"" Washburne"
"3","Pastor Veal"
"4","Tucker"
"5","Simon"
"6","Sonny"
"7","Wat\"
次に、行をロードしないこともできます:
mysql> DELETE FROM person;
Query OK, 11 rows affected (0.00 sec)
mysql> LOAD DATA
LOCAL INFILE 'temp-2.csv'
INTO TABLE person
FIELDS
TERMINATED BY ','
ENCLOSED BY '"'
ESCAPED BY '"'
LINES
TERMINATED BY '\n'
IGNORE 1 LINES
;
Query OK, 0 rows affected (0.00 sec)
Records: 0 Deleted: 0 Skipped: 0 Warnings: 0
mysql> SELECT * FROM person;
Empty set (0.00 sec)
または、ヘッダーを含むすべての行をロードできます。
mysql> DELETE FROM person;
Query OK, 0 rows affected (0.00 sec)
mysql> LOAD DATA
LOCAL INFILE 'temp-2.csv'
INTO TABLE person
FIELDS
TERMINATED BY ','
ENCLOSED BY '"'
ESCAPED BY '"'
LINES
TERMINATED BY '\n'
IGNORE 0 LINES
;
Query OK, 9 rows affected, 1 warning (0.03 sec)
Records: 9 Deleted: 0 Skipped: 0 Warnings: 1
mysql> show warnings;
+---------+------+--------------------------------------------------------+
| Level | Code | Message |
+---------+------+--------------------------------------------------------+
| Warning | 1366 | Incorrect integer value: 'ID' for column 'ID' at row 1 |
+---------+------+--------------------------------------------------------+
1 row in set (0.00 sec)
mysql> SELECT * FROM person;
+------+------------------------+
| ID | UID |
+------+------------------------+
| 0 | UID |
| 0 | Steve the Pirate |
| 1 | \Alpha |
| 2 | Hoban "Wash" Washburne |
| 3 | Pastor Veal |
| 4 | Tucker |
| 5 | Simon |
| 6 | Sonny |
| 7 | Wat\ |
+------+------------------------+
9 rows in set (0.00 sec)
間違った方法をたくさん発見したのでLOAD DATA、これらのファイルからデータベースにデータをインポートするにはどうすればよいでしょうか?