手把手教你如何扩展（破解）mybatisplus的sql生成 - ToB企服应用市场:ToB评测及商务社交产业平台

/**
* 新增一个通用sql
*/
public class SelectByErp extends AbstractMethod {
// 需要查询的列名
private final String erpColumn = "erp";
// sql方法名
private final String method = "selectByErp";
// sql模板
private final String sqlTemplate = "SELECT %s FROM %s WHERE %s=#{%s} %s";
@Override
public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) {
// 获取需要查询的字段名及属性名
TableFieldInfo erpFiled = getErpProperty(tableInfo);
// 拼接组装sql
SqlSource sqlSource = new RawSqlSource(configuration, String.format(sqlTemplate,
sqlSelectColumns(tableInfo, false),
tableInfo.getTableName(),
erpFiled.getColumn(), erpFiled.getProperty(),
tableInfo.getLogicDeleteSql(true, false)), Object.class);
return this.addSelectMappedStatementForTable(mapperClass, method, sqlSource, tableInfo);
}
/**
* 查询erp列信息
*/
private TableFieldInfo getErpProperty(TableInfo tableInfo) {
List<TableFieldInfo> fieldList = tableInfo.getFieldList();
TableFieldInfo erpField = fieldList.stream().filter(filed -> filed.getColumn().equals(erpColumn)).findFirst().get();
return erpField;
}

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// 需注入到spring容器中
@Component
public class GyhSqlInjector extends DefaultSqlInjector {
@Override
public List<AbstractMethod> getMethodList(Class<?> mapperClass) {
List<AbstractMethod> methodList = super.getMethodList(mapperClass);
// 增加 SelectByErp对象，程序启动后自动加载
methodList.add(new SelectByErp());
return methodList;
}
}

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/**
* 自定义的通用Mapper
*/
public interface GyhBaseMapper<T> extends BaseMapper<T> {
List<T> selectByErp(String erp);
}

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public interface XXXMapper extends GyhBaseMapper<XXXTable>

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@Component
public class GyhSqlInjector extends DefaultSqlInjector {
@Override
public List<AbstractMethod> getMethodList(Class<?> mapperClass) {
List<AbstractMethod> methodList = super.getMethodList(mapperClass);
// 添加 AlwaysUpdateSomeColumnById 对象
methodList.add(new AlwaysUpdateSomeColumnById());
return methodList;
}
}

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/**
* 自定义的通用Mapper
*/
public interface GyhBaseMapper<T> extends BaseMapper<T> {
int alwaysUpdateSomeColumnById(@Param(Constants.ENTITY) T entity);
}

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/**
* 自定义的通用Mapper
*/
public interface GyhBaseMapper<T> extends BaseMapper<T> {
int alwaysUpdateSomeColumnById(@Param(Constants.ENTITY) T entity);
}

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public class UpdateByIdWithSharding extends UpdateById {
private String columnDot = "`";
private YamlShardingRuleConfiguration yamlShardingRuleConfiguration;
// 注入shardingsphere的分库分表配置信息
public UpdateByIdWithSharding(YamlShardingRuleConfiguration yamlShardingRuleConfiguration) {
this.yamlShardingRuleConfiguration = yamlShardingRuleConfiguration;
}
@Override
public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) {
String tableName = tableInfo.getTableName();
// shardingsphere 分库分表配置信息
Map<String, YamlTableRuleConfiguration> tables = yamlShardingRuleConfiguration.getTables();
// 判断当前表是否设置了分表字段
if (tables.containsKey(tableName)) {
YamlTableRuleConfiguration tableRuleConfiguration = tables.get(tableName);
// 获取分表字段
String shardingColumn = tableRuleConfiguration.getTableStrategy().getStandard().getShardingColumn();
// 构建sql
boolean logicDelete = tableInfo.isLogicDelete();
SqlMethod sqlMethod = SqlMethod.UPDATE_BY_ID;
// 增加分表字段判断
String shardingAdditional = getShardingColumnWhere(tableInfo, shardingColumn);
// 是否判断逻辑删除字段
final String additional = optlockVersion() + tableInfo.getLogicDeleteSql(true, false);
shardingAdditional = shardingAdditional + additional;
String sql = String.format(sqlMethod.getSql(), tableInfo.getTableName(),
getSqlSet(logicDelete, tableInfo, shardingColumn),
tableInfo.getKeyColumn(), ENTITY_DOT + tableInfo.getKeyProperty(),
shardingAdditional);
SqlSource sqlSource = languageDriver.createSqlSource(configuration, sql, modelClass);
return addUpdateMappedStatement(mapperClass, modelClass, sqlMethod.getMethod(), sqlSource);
} else {
return super.injectMappedStatement(mapperClass, modelClass, tableInfo);
}
}
/**
* where条件增加分表字段
*/
private String getShardingColumnWhere(TableInfo tableInfo, String shardingColumn) {
StringBuilder shardingWhere = new StringBuilder();
shardingWhere.append(" AND ").append(shardingColumn).append("=#{");
shardingWhere.append(ENTITY_DOT);
TableFieldInfo fieldInfo = tableInfo.getFieldList().stream()
.filter(f -> f.getColumn().replaceAll(columnDot, StringUtils.EMPTY).equals(shardingColumn))
.findFirst().get();
shardingWhere.append(fieldInfo.getEl());
shardingWhere.append("}");
return shardingWhere.toString();
}
/**
* set模块去掉分表字段
*/
public String getSqlSet(boolean ignoreLogicDelFiled, TableInfo tableInfo, String shardingColumn) {
List<TableFieldInfo> fieldList = tableInfo.getFieldList();
// 去掉分表字段的set设置，即不修改分表字段
String rmShardingColumnSet = fieldList.stream()
.filter(i -> ignoreLogicDelFiled ? !(tableInfo.isLogicDelete() && i.isLogicDelete()) : true)
.filter(i -> !i.getColumn().equals(shardingColumn))
.map(i -> i.getSqlSet(ENTITY_DOT))
.filter(Objects::nonNull).collect(joining(NEWLINE));
return rmShardingColumnSet;
}
}

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// 需注入到spring容器中
@Component
public class GyhSqlInjector extends DefaultSqlInjector {
/**
* shardingsphere 配置信息
*/
@Autowired
private YamlShardingRuleConfiguration yamlShardingRuleConfiguration;
@Override
public List<AbstractMethod> getMethodList(Class<?> mapperClass) {
List<AbstractMethod> methodList = super.getMethodList(mapperClass);
// 添加 UpdateByIdWithSharding 对象，并注入分库分表信息
methodList.add(new UpdateByIdWithSharding(yamlShardingRuleConfiguration));
return methodList;
}
}

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/**
* 自定义的通用Mapper
*/
public interface GyhBaseMapper<T> extends BaseMapper<T> {
int updateById(@Param(Constants.ENTITY) T entity);
}

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