mysql保留字,MySQL关键字-保留字

今天写一个数据库更新语句，检查了N遍都没有检查出哪里错误，后来发现只要去掉 key=$key就可以正常运行，后来去群里面一问，原来key是MySQL的关键字，不能使用的，难怪我觉得奇怪，成功了几百次的更新语句居然会失败，给key加上``（键盘1左边那个符号，不是逗号）变成`key`就行了。
MySQL关键字-保留字
ADDALLALTERANALYZEANDASASCASENSITIVEBEFOREBETWEENBIGINTBINARYBLOBBOTHBYCALLCASCADECASECHANGECHARCHARACTERCHECKCOLLATECOLUMNCONDITIONCONNECTIONCONSTRAINTCONTINUECONVERTCREATECROSSCURRENT_DATECURRENT_TIMECURRENT_TIMESTAMPCURRENT_USERCURSORDATABASEDATABASESDAY_HOURDAY_MICROSECONDDAY_MINUTEDAY_SECONDDECDECIMALDECLAREDEFAULTDELAYEDDELETEDESCDESCRIBEDETERMINISTICDISTINCTDISTINCTROWDIVDOUBLEDROPDUALEACHELSEELSEIFENCLOSEDESCAPEDEXISTSEXITEXPLAINFALSEFETCHFLOATFLOAT4FLOAT8FORFORCEFOREIGNFROMFULLTEXTGOTOGRANTGROUPHAVINGHIGH_PRIORITYHOUR_MICROSECONDHOUR_MINUTEHOUR_SECONDIFIGNOREININDEXINFILEINNERINOUTINSENSITIVEINSERTINTINT1INT2INT3INT4INT8INTEGERINTERVALINTOISITERATEJOINKEYKEYSKILLLABELLEADINGLEAVELEFTLIKELIMITLINEARLINESLOADLOCALTIMELOCALTIMESTAMPLOCKLONGLONGBLOBLONGTEXTLOOPLOW_PRIORITYMATCHMEDIUMBLOBMEDIUMINTMEDIUMTEXTMIDDLEINTMINUTE_MICROSECONDMINUTE_SECONDMODMODIFIESNATURALNOTNO_WRITE_TO_BINLOGNULLNUMERICONOPTIMIZEOPTIONOPTIONALLYORORDEROUTOUTEROUTFILEPRECISIONPRIMARYPROCEDUREPURGERAID0RANGEREADREADSREALREFERENCESREGEXPRELEASERENAMEREPEATREPLACEREQUIRERESTRICTRETURNREVOKERIGHTRLIKESCHEMASCHEMASSECOND_MICROSECONDSELECTSENSITIVESEPARATORSETSHOWSMALLINTSPATIALSPECIFICSQLSQLEXCEPTIONSQLSTATESQLWARNINGSQL_BIG_RESULTSQL_CALC_FOUND_ROWSSQL_SMALL_RESULTSSLSTARTINGSTRAIGHT_JOINTABLETERMINATEDTHENTINYBLOBTINYINTTINYTEXTTOTRAILINGTRIGGERTRUEUNDOUNIONUNIQUEUNLOCKUNSIGNEDUPDATEUSAGEUSEUSINGUTC_DATEUTC_TIMEUTC_TIMESTAMPVALUESVARBINARYVARCHARVARCHARACTERVARYINGWHENWHEREWHILEWITHWRITEX509XORYEAR_MONTHZEROFILL
MySQL允许部分关键字用做未引起来的识别符，因为许多人以前曾使用过它们。下面列出了一些例子：
ACTION
BIT
DATE
ENUM
NO
TEXT
TIME
TIMESTAMP

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