【轉】 mysql反引號的使用(防沖突)
阿新 • • 發佈:2018-05-17
rev delete 僅供參考 cte each 必須 repl exc 沖突
引號一般用在字段的值,如果字段值是字符或字符串,則要加引號,如:select=‘字段值‘
不加反引號建的表不能包含MYSQL保留字,否則出錯
5、mysql常見的保留字
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使用mysql時一定要註意,不要使用它的保留字作為表名或者列名,否則會出現莫名其妙的錯誤。
昨天建了一個表,其中一列名為interval(時間間隔),結果數據死都插不進去,最後才發現原來interval是mysql的保留字。
以後出現類似的錯誤要先想想是不是因為表名或列名沖突造成的啊。
從網上找了一個mysql的保留字列表,僅供參考。
註:MySQL允許部分關鍵字用做未引起來的識別符,因為許多人以前曾使用過它們。
如:ACTION、BIT、DATE、ENUM、NO、TEXT、TIME、TIMESTAMP
轉載地址:http://blog.itechol.com/space.php?uid=33&do=blog&id=6681
1、mysql語句中 反引號 【`】作用: 避免表明、字段名與mysql已存在的【保留字】沖突,引起不知名錯誤。
2、所以我們建表和字段時候,特別需要註意,盡量使用全拼/下劃線 來設置字段和表名
3、連接不同數據庫查詢,一定不要加【`】反引號,否則會被解析成 單個表
4、為了區分MYSQL的保留字與普通字符而引入的符號。
舉個例子:SELECT `select` FROM `test` WHERE select=‘字段值‘ 在test表中,有個select字段,如果不用反引號,MYSQL將把select視為保留字而導致出錯,所以,有MYSQL保留字作為字段的,必須加上反引號來區分。ADD | ALL | ALTER |
ANALYZE | AND | AS |
ASC | ASENSITIVE | BEFORE |
BETWEEN | BIGINT | BINARY |
BLOB | BOTH | BY |
CALL | CASCADE | CASE |
CHANGE | CHAR | CHARACTER |
CHECK | COLLATE | COLUMN |
CONDITION | CONNECTION | CONSTRAINT |
CONTINUE | CONVERT | CREATE |
CROSS | CURRENT_DATE | CURRENT_TIME |
CURRENT_TIMESTAMP | CURRENT_USER | CURSOR |
DATABASE | DATABASES | DAY_HOUR |
DAY_MICROSECOND | DAY_MINUTE | DAY_SECOND |
DEC | DECIMAL | DECLARE |
DEFAULT | DELAYED | DELETE |
DESC | DESCRIBE | DETERMINISTIC |
DISTINCT | DISTINCTROW | DIV |
DOUBLE | DROP | DUAL |
EACH | ELSE | ELSEIF |
ENCLOSED | ESCAPED | EXISTS |
EXIT | EXPLAIN | FALSE |
FETCH | FLOAT | FLOAT4 |
FLOAT8 | FOR | FORCE |
FOREIGN | FROM | FULLTEXT |
GOTO | GRANT | GROUP |
HAVING | HIGH_PRIORITY | HOUR_MICROSECOND |
HOUR_MINUTE | HOUR_SECOND | IF |
IGNORE | IN | INDEX |
INFILE | INNER | INOUT |
INSENSITIVE | INSERT | INT |
INT1 | INT2 | INT3 |
INT4 | INT8 | INTEGER |
INTERVAL | INTO | IS |
ITERATE | JOIN | KEY |
KEYS | KILL | LABEL |
LEADING | LEAVE | LEFT |
LIKE | LIMIT | LINEAR |
LINES | LOAD | LOCALTIME |
LOCALTIMESTAMP | LOCK | LONG |
LONGBLOB | LONGTEXT | LOOP |
LOW_PRIORITY | MATCH | MEDIUMBLOB |
MEDIUMINT | MEDIUMTEXT | MIDDLEINT |
MINUTE_MICROSECOND | MINUTE_SECOND | MOD |
MODIFIES | NATURAL | NOT |
NO_WRITE_TO_BINLOG | NULL | NUMERIC |
ON | OPTIMIZE | OPTION |
OPTIONALLY | OR | ORDER |
OUT | OUTER | OUTFILE |
PRECISION | PRIMARY | PROCEDURE |
PURGE | RAID0 | RANGE |
READ | READS | REAL |
REFERENCES | REGEXP | RELEASE |
RENAME | REPEAT | REPLACE |
REQUIRE | RESTRICT | RETURN |
REVOKE | RIGHT | RLIKE |
SCHEMA | SCHEMAS | SECOND_MICROSECOND |
SELECT | SENSITIVE | SEPARATOR |
SET | SHOW | SMALLINT |
SPATIAL | SPECIFIC | SQL |
SQLEXCEPTION | SQLSTATE | SQLWARNING |
SQL_BIG_RESULT | SQL_CALC_FOUND_ROWS | SQL_SMALL_RESULT |
SSL | STARTING | STRAIGHT_JOIN |
TABLE | TERMINATED | THEN |
TINYBLOB | TINYINT | TINYTEXT |
TO | TRAILING | TRIGGER |
TRUE | UNDO | UNION |
UNIQUE | UNLOCK | UNSIGNED |
UPDATE | USAGE | USE |
USING | UTC_DATE | UTC_TIME |
UTC_TIMESTAMP | VALUES | VARBINARY |
VARCHAR | VARCHARACTER | VARYING |
WHEN | WHERE | WHILE |
WITH | WRITE | X509 |
XOR | YEAR_MONTH | ZEROFILL |
【轉】 mysql反引號的使用(防沖突)