[英]Integrity constraint violation: unique constraint or index violation HSQLDB
例如,如果我添加new Department(new BigInteger("50"), "ODD", "SPB")
,所有工作,它的值都插入到数据库中。 但是如果我想再次插入例如new Department(new BigInteger("50"), "ODDMOD", "SPBMOD")
,出现java.sql.SQLIntegrityConstraintViolationException: integrity constraint violation: unique constraint or index violation; SYS_PK_10092 table: DEPARTMENT
java.sql.SQLIntegrityConstraintViolationException: integrity constraint violation: unique constraint or index violation; SYS_PK_10092 table: DEPARTMENT
。 我知道不能插入具有相同主键的值,但是如果存在主键或其他解决方案,如何更新值?
public Department save(Department department) throws SQLException {
Connection connection = ConnectionSource.instance().createConnection();
String sql = "insert into department values (?, ?, ?)";
PreparedStatement statement = connection.prepareStatement(sql);
statement.setLong(1, Long.parseLong(String.valueOf(department.getId())));
statement.setString(2, department.getName());
statement.setString(3, department.getLocation());
statement.executeUpdate();
PreparedStatement st = connection.prepareStatement("select * from department where id = ? ");
st.setLong(1, Long.parseLong(String.valueOf(department.getId())));
ResultSet resultSet = st.executeQuery();
resultSet.next();
Department demper = new Department(
new BigInteger(String.valueOf(resultSet.getInt("id"))),
resultSet.getString("name"),
resultSet.getString("location")
);
return demper;
}
你想要一个 upsert 在这里:
public Department save(Department department) throws SQLException {
Connection connection = ConnectionSource.instance().createConnection();
String sql = "MERGE INTO department d1 " +
"USING (VALUES ?, ?, ?) d2 (id, name, location) " +
" ON (d1.id = d2.id) " +
" WHEN MATCHED THEN UPDATE SET " +
" d1.name = d2.name, d1.location = d2.location " +
" WHEN NOT MATCHED THEN INSERT (id, name, location) VALUES (d2.id, d2.name, d2.location)";
PreparedStatement statement = connection.prepareStatement(sql);
// execute merge here as before
statement.setLong(1, Long.parseLong(String.valueOf(department.getId())));
statement.setString(2, department.getName());
statement.setString(3, department.getLocation());
statement.executeUpdate();
// ...
}
如果部门id
不存在于表中,则MERGE
会执行插入操作。 否则它将进行更新。 请注意,如果您从纯 JDBC 转换到 JPA/Hibernate,则 JPA save()
方法可以在后台自动为您更新插入。
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