php - 使用php在服务器端数据表中内连接

Question

//define index of column
    $columns = array( 
        0 =>'id',
        1 =>'employee_name', 
        2 => 'employee_salary',
        3 => 'employee_age'
        4 =>'employee_City', 
        5 => 'employee_State',
        6 => 'employee_Pin'
    );

    $where = $sqlTot = $sqlRec = "";
    if( !empty($params['search']['value']) ) {   
        $where .=" WHERE ";
        $where .=" ( employee_name LIKE '".$params['search']['value']."%' ";    
        $where .=" OR employee_salary LIKE '".$params['search']['value']."%' ";

        $where .=" OR employee_age LIKE '".$params['search']['value']."%' )";
    }
    // getting total number records without any search
    $sql = "SELECT * FROM `employee` ";
    $sqlTot .= $sql;
    $sqlRec .= $sql;
    //concatenate search sql if value exist
    if(isset($where) && $where != '') {

        $sqlTot .= $where;
        $sqlRec .= $where;
    }

请帮帮我，我有 3 个表，所有表都有一个主键作为 table_id 如何使用服务器端数据表从 3 个表获取数据如何在此代码中实现联接查询。这里employee_City、employee_State 和employee_Pin 存储在第二个表中。雇用个人详细信息存储在第三个表中。如何连接所有表？

Answer 1

我刚刚获取了表城市、州、密码的虚拟名称..

尝试使用此查询:

$sql = "SELECT id, employee_name, employee_salary, employee_age, employee_City, employee_State, employee_Pin FROM employee LEFT JOIN city ON employee.cityID = city.id  LEFT JOIN state ON employee.stateID = state.id  LEFT JOIN pincode ON employee.pincodeid = pincode.id  ";

  if( !empty($params['search']['value']) ) {   
        $sql .=" WHERE ";
        $sql .=" ( employee_name LIKE '%".$params['search']['value']."%' ";    
        $sql .=" OR employee_salary LIKE '%".$params['search']['value']."%' ";
        $sql .=" OR employee_age LIKE '%".$params['search']['value']."%' )";
    }
$sql.=" ORDER BY employee_name";