Mysql判断表字段或索引是否存在
判断字段是否存在：
DROPPROCEDUREIFEXISTSschema_change; DELIMITER// CREATEPROCEDUREschema_change()BEGIN DECLARECurrentDatabaseVARCHAR(); SELECTDATABASE()INTOCurrentDatabase; IFNOTEXISTS(SELECT*FROMinformation_schema.columnsWHEREtable_schema=CurrentDatabaseANDtable_name='rtc_order'ANDcolumn_name='IfUpSend')THEN ALTERTABLErtc_order ADDCOLUMN`IfUpSend`BITNOTNULLDEFAULTCOMMENT'是否上传是否上传'; ENDIF; END// DELIMITER; CALLschema_change();
判断索引是否存在：
DROPPROCEDUREIFEXISTSschema_change; DELIMITER// CREATEPROCEDUREschema_change()BEGIN DECLARECurrentDatabaseVARCHAR(); SELECTDATABASE()INTOCurrentDatabase; IFNOTEXISTS(SELECT*FROMinformation_schema.statisticsWHEREtable_schema=CurrentDatabaseANDtable_name='rtc_phototype'ANDindex_name='index_name')THEN ALTERTABLE`rtc_Phototype`ADDINDEXindex_name(`imgtype`); ENDIF; END// DELIMITER; CALLschema_change();
从这两段可以看出很多东西，具体可以自己试验一下
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