使用mybatis的generator自动生成代码,但是oracle数据库中number(6,2)总是自动转成BigDecimal,我想要转成的是float类型 这样就写了一个类型转换器,需要继承JavaTypeResolver接口 然后在mybaties配置文件generatorConfig.xml中类型转换配置位置添加上即可 j
使用mybatis的generator自动生成代码,但是oracle数据库中number(6,2)总是自动转成BigDecimal,我想要转成的是float类型
这样就写了一个类型转换器,需要继承JavaTypeResolver接口
然后在mybaties配置文件generatorConfig.xml中类型转换配置位置添加上即可
<javaTypeResolver type="com.generator.MyJavaTypeResolver"> <property name="forceBigDecimals" value="false" /> <!-- 类型解析器 --> </javaTypeResolver>类型转换器MyJavaTypeResolver主要代码
public FullyQualifiedJavaType calculateJavaType( IntrospectedColumn introspectedColumn) { // TODO Auto-generated method stub FullyQualifiedJavaType answer; JdbcTypeInformation jdbcTypeInformation = typeMap .get(introspectedColumn.getJdbcType()); if (jdbcTypeInformation == null) { switch (introspectedColumn.getJdbcType()) { case Types.DECIMAL: case Types.NUMERIC: if(introspectedColumn.getScale() > 0) {//如果包含小数点则转换成float answer = new FullyQualifiedJavaType(Float.class.getName()); }else{ if ( introspectedColumn.getLength() > 18 || forceBigDecimals) { answer = new FullyQualifiedJavaType(BigDecimal.class .getName()); } else if (introspectedColumn.getLength() > 9) { answer = new FullyQualifiedJavaType(Long.class.getName()); } else if (introspectedColumn.getLength() > 4) { answer = new FullyQualifiedJavaType(Integer.class.getName()); } else { answer = new FullyQualifiedJavaType(Short.class.getName()); } } break; default: answer = null; break; } } else { answer = jdbcTypeInformation.getFullyQualifiedJavaType(); } return answer; }

Mastering the method of adding MySQL users is crucial for database administrators and developers because it ensures the security and access control of the database. 1) Create a new user using the CREATEUSER command, 2) Assign permissions through the GRANT command, 3) Use FLUSHPRIVILEGES to ensure permissions take effect, 4) Regularly audit and clean user accounts to maintain performance and security.

ChooseCHARforfixed-lengthdata,VARCHARforvariable-lengthdata,andTEXTforlargetextfields.1)CHARisefficientforconsistent-lengthdatalikecodes.2)VARCHARsuitsvariable-lengthdatalikenames,balancingflexibilityandperformance.3)TEXTisidealforlargetextslikeartic

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ToaddauserremotelytoMySQL,followthesesteps:1)ConnecttoMySQLasroot,2)Createanewuserwithremoteaccess,3)Grantnecessaryprivileges,and4)Flushprivileges.BecautiousofsecurityrisksbylimitingprivilegesandaccesstospecificIPs,ensuringstrongpasswords,andmonitori

TostorestringsefficientlyinMySQL,choosetherightdatatypebasedonyourneeds:1)UseCHARforfixed-lengthstringslikecountrycodes.2)UseVARCHARforvariable-lengthstringslikenames.3)UseTEXTforlong-formtextcontent.4)UseBLOBforbinarydatalikeimages.Considerstorageov

When selecting MySQL's BLOB and TEXT data types, BLOB is suitable for storing binary data, and TEXT is suitable for storing text data. 1) BLOB is suitable for binary data such as pictures and audio, 2) TEXT is suitable for text data such as articles and comments. When choosing, data properties and performance optimization must be considered.

No,youshouldnotusetherootuserinMySQLforyourproduct.Instead,createspecificuserswithlimitedprivilegestoenhancesecurityandperformance:1)Createanewuserwithastrongpassword,2)Grantonlynecessarypermissionstothisuser,3)Regularlyreviewandupdateuserpermissions

MySQLstringdatatypesshouldbechosenbasedondatacharacteristicsandusecases:1)UseCHARforfixed-lengthstringslikecountrycodes.2)UseVARCHARforvariable-lengthstringslikenames.3)UseBINARYorVARBINARYforbinarydatalikecryptographickeys.4)UseBLOBorTEXTforlargeuns


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