Java中获取Postgresql错误码（getErrorCode/getSQLState）

总结

如果从Oracle迁移到PG，请把Java中的getErrorCode替换为getSQLState，并适当修改代码逻辑，因为Oracle和PG的错误码没有任何对应关系。

下面表格中列举了一些异常场景，无论执行哪种JAVA中都会抛出SQLException，在异常处理中可以通过三种接口拿到错误信息：

• getErrorCode
• getSQLState
• getMessage

例如：

代码语言：javascript复制

...
        } catch (SQLException e) {
            e.printStackTrace();
            System.out.println(e.getErrorCode());
            System.out.println(e.getSQLState());
            System.out.println(e.getMessage());
...

每种场景总结：

异常场景	e.getErrorCode()	e.getSQLState()	e.getMessage()
RAISE division_by_zero;	0	22012	ERROR: division_by_zero
RAISE SQLSTATE ‘20018’;	0	20018	ERROR: 20018
raise exception ‘a’;	0	P0001	ERROR: a
raise exception using errcode=‘20126’, message=‘this message 20126’;	0	20126	ERROR: this message 20126
i := 1 / 0;	0	22012	ERROR: division by zero

与Oracle的区别：

• PG实现了getSQLState、getMessage两种接口，但getErrorCode永远是0。
• 而Oracle也实现了getErrorCode接口，可以拿到Oracle特有的负整数错误码。

实例

代码语言：javascript复制

package org.example;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class Main {
    public static void main(String[] args) throws Exception {
        String url = "jdbc:postgresql://1.2.3.4:1234/postgres";
        Connection conn = null;

        try {
            Class.forName("org.postgresql.Driver");

            conn = DriverManager.getConnection(url, "xxx", "xxx");
            System.out.println("Database connected");

            Statement stmt = conn.createStatement();
            stmt.execute(
            """
            create or replace procedure p_err_test1()
            as $$
            DECLARE
              text_var1 text;
              text_var4 text;
            BEGIN
              raise notice 'in p_err_test1';
            
              RAISE division_by_zero;
              -- RAISE SQLSTATE '-20018';
              -- raise exception 'a';
              raise exception using errcode='20126', message='this message 20126';
            -- EXCEPTION WHEN OTHERS THEN
            --   GET STACKED DIAGNOSTICS text_var1 = MESSAGE_TEXT,
            --                           text_var4 = RETURNED_SQLSTATE;
            
            --   raise notice 'MESSAGE_TEXT: %', text_var1;
            --   raise notice 'RETURNED_SQLSTATE: %', text_var4;
            END;
            $$ language plpgsql
            """);
            stmt.execute("call p_err_test1()");


            stmt.close();
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
            System.out.println(e.getErrorCode());
            System.out.println(e.getSQLState());
            System.out.println(e.getMessage());

        } finally {
            // release resource ....
        }
    }
}

maven

代码语言：javascript复制

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>pgjdbc17</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>42.2.27.jre7</version>
        </dependency>

    </dependencies>
</project>

java postgresql import 接口 异常

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