这两天开了一个新项目,使用SpringBoot+SpringData, 刚做了一个小功能,都是一张表的操作没什么问题,今天设计到了两张表联查,两张表各取了几个字段,组合成了一个vo, 当我用原生sql查询时报出 “找不到转换器”,当我用JPQL查询时,报出 xxx is not mapped.。 着实浪费了些时间。 其实最大的根本原因在于, 当使用JPQL 查询时,我们 FROM 的表名就不能是实体上@Table 注解中的表名,而是对应的实体的类名,记住是类名,并且查询的字段要是 实体类的属性,而不是数据库字段。切记。下面是我的代码
package com.wisdombud.dama.quality.datasource.pojo; import java.io.Serializable; import java.util.Date; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.SequenceGenerator; import javax.persistence.Table; import javax.validation.constraints.NotBlank; import com.fasterxml.jackson.annotation.JsonFormat; import lombok.ToString; @Entity @Table(name = "DATA_SOURCE") @SequenceGenerator(name = "ID_SEQ", sequenceName = "SEQ_DATA_SOURCE", allocationSize = 1) @ToString public class DataSourcePojo implements Serializable{ private static final long serialVersionUID = 4658654420795590006L; private Long id; @NotBlank(message = "数据源名称不能为空!") private String name; @NotBlank(message = "ip地址不能为空!") private String ip; @NotBlank(message = "端口号不能为空!") private String port; @NotBlank(message = "服务名不能为空!") private String serviceName; @NotBlank(message = "用户名不能为空!") private String userName; @NotBlank(message = "密码不能为空!") private String password; private String managerBranch; private String leadingCadre; private String phone; private Long sortIndex; private String remark; private Long createUserId; private String createUserName; @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8") private Date createTime; private Date lastUpdateTime; private String re1; private String re2; private String re3; private String re4; @Id @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "ID_SEQ") @Column(name = "ID", unique = true, nullable = false, precision = 18, scale = 0) public Long getId() { return id; } public void setId(Long id) { this.id = id; } @Column(name = "NAME") public String getName() { return name; } public void setName(String name) { this.name = name; } @Column(name = "IP") public String getIp() { return ip; } public void setIp(String ip) { this.ip = ip; } @Column(name = "PORT") public String getPort() { return port; } public void setPort(String port) { this.port = port; } @Column(name = "SERVICE_NAME") public String getServiceName() { return serviceName; } public void setServiceName(String serviceName) { this.serviceName = serviceName; } @Column(name = "USER_NAME") public String getUserName() { return userName; } public void setUserName(String userName) { this.userName = userName; } @Column(name = "PASSWORD") public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } @Column(name = "MANAGER_BRANCH") public String getManagerBranch() { return managerBranch; } public void setManagerBranch(String managerBranch) { this.managerBranch = managerBranch; } @Column(name = "LEADING_CADRE") public String getLeadingCadre() { return leadingCadre; } public void setLeadingCadre(String leadingCadre) { this.leadingCadre = leadingCadre; } @Column(name = "PHONE") public String getPhone() { return phone; } public void setPhone(String phone) { this.phone = phone; } @Column(name = "SORT_INDEX") public Long getSortIndex() { return sortIndex; } public void setSortIndex(Long sortIndex) { this.sortIndex = sortIndex; } @Column(name = "REMARK") public String getRemark() { return remark; } public void setRemark(String remark) { this.remark = remark; } @Column(name = "CREATE_USER_ID") public Long getCreateUserId() { return createUserId; } public void setCreateUserId(Long createUserId) { this.createUserId = createUserId; } @Column(name = "CREATE_USER_NAME") public String getCreateUserName() { return createUserName; } public void setCreateUserName(String createUserName) { this.createUserName = createUserName; } @Column(name = "CREATE_TIME") public Date getCreateTime() { return createTime; } public void setCreateTime(Date createTime) { this.createTime = createTime; } @Column(name = "LAST_UPDATE_TIME") public Date getLastUpdateTime() { return lastUpdateTime; } public void setLastUpdateTime(Date lastUpdateTime) { this.lastUpdateTime = lastUpdateTime; } @Column(name = "RE1") public String getRe1() { return re1; } public void setRe1(String re1) { this.re1 = re1; } @Column(name = "RE2") public String getRe2() { return re2; } public void setRe2(String re2) { this.re2 = re2; } @Column(name = "RE3") public String getRe3() { return re3; } public void setRe3(String re3) { this.re3 = re3; } @Column(name = "RE4") public String getRe4() { return re4; } public void setRe4(String re4) { this.re4 = re4; } }
package com.wisdombud.dama.quality.datasource.tablerelation.pojo; import java.io.Serializable; import java.util.Date; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.SequenceGenerator; import javax.persistence.Table; import lombok.ToString; /** * 表关系实体 * @author qiaoyutao * @Date: 2019年7月4日 上午11:40:10 */ @Entity @Table(name = "TABLE_RELATION") @SequenceGenerator(name = "ID_SEQ", sequenceName = "SEQ_TABLE_RELATION", allocationSize = 1) @ToString public class TableRelationPojo implements Serializable{ private static final long serialVersionUID = -9058973373224769393L; private Long id; private Long dataSourceId; private String tableName; private String columnName; private String relationTableName; private String relationColumnName; private String remark; private Long createUserId; private String createUserName; private Date createTime; private Date lastUpdateTime; private String re1; private String re2; private String re3; private String re4; @Id @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "ID_SEQ") @Column(name = "ID", unique = true, nullable = false, precision = 18, scale = 0) public Long getId() { return id; } public void setId(Long id) { this.id = id; } @Column(name = "DATA_SOURCE_ID") public Long getDataSourceId() { return dataSourceId; } public void setDataSourceId(Long dataSourceId) { this.dataSourceId = dataSourceId; } @Column(name = "TABLE_NAME") public String getTableName() { return tableName; } public void setTableName(String tableName) { this.tableName = tableName; } @Column(name = "COLUMN_NAME") public String getColumnName() { return columnName; } public void setColumnName(String columnName) { this.columnName = columnName; } @Column(name = "RELATION_TABLE_NAME") public String getRelationTableName() { return relationTableName; } public void setRelationTableName(String relationTableName) { this.relationTableName = relationTableName; } @Column(name = "RELATION_COLUMN_NAME") public String getRelationColumnName() { return relationColumnName; } public void setRelationColumnName(String relationColumnName) { this.relationColumnName = relationColumnName; } @Column(name = "REMARK") public String getRemark() { return remark; } public void setRemark(String remark) { this.remark = remark; } @Column(name = "CREATE_USER_ID") public Long getCreateUserId() { return createUserId; } public void setCreateUserId(Long createUserId) { this.createUserId = createUserId; } @Column(name = "CREATE_USER_NAME") public String getCreateUserName() { return createUserName; } public void setCreateUserName(String createUserName) { this.createUserName = createUserName; } @Column(name = "CREATE_TIME") public Date getCreateTime() { return createTime; } public void setCreateTime(Date createTime) { this.createTime = createTime; } @Column(name = "LAST_UPDATE_TIME") public Date getLastUpdateTime() { return lastUpdateTime; } public void setLastUpdateTime(Date lastUpdateTime) { this.lastUpdateTime = lastUpdateTime; } @Column(name = "RE1") public String getRe1() { return re1; } public void setRe1(String re1) { this.re1 = re1; } @Column(name = "RE2") public String getRe2() { return re2; } public void setRe2(String re2) { this.re2 = re2; } @Column(name = "RE3") public String getRe3() { return re3; } public void setRe3(String re3) { this.re3 = re3; } @Column(name = "RE4") public String getRe4() { return re4; } public void setRe4(String re4) { this.re4 = re4; } }
下面是我的dao层,重点
package com.wisdombud.dama.quality.datasource.tablerelation.dao; import org.springframework.data.domain.Page; import org.springframework.data.domain.Pageable; import org.springframework.data.jpa.repository.JpaRepository; import org.springframework.data.jpa.repository.JpaSpecificationExecutor; import org.springframework.data.jpa.repository.Query; import com.wisdombud.dama.quality.datasource.tablerelation.pojo.TableRelationPojo; import com.wisdombud.dama.quality.datasource.tablerelation.vo.TableRelationGridVo; public interface TableRelationDao extends JpaRepository, JpaSpecificationExecutor { // 这里使用JPQL来写的, 区别就是 new 一个vo名,最好带上全路径,并且vo中要有有参构造器,构造器签名要与查询的字段一致, 查询的属性都是实体类中的属性名,不是数据库的字段名,这点切记。 @Query(value = "SELECT new com.wisdombud.dama.quality.datasource.tablerelation.vo.TableRelationGridVo(re.id, " + "ds.name, re.tableName, re.columnName, " + "re.relationTableName, re.relationColumnName, " + "re.createTime) " + "FROM TableRelationPojo re left join DataSourcePojo ds on re.dataSourceId = ds.id") public Page page(Pageable pageable); }
希望能够帮到跟我一样因为这一个,加班到9点的你。 转载请注明出处