Question

我正在使用查询("SHOW COLUMNS FROM XYZ_table").它显示出像

一样

Array ( [Field] => policyID [Type] => int(10) [Null] => YES [Key] => [Default] => [Extra] => ).

我只关注PolicyID，其类型=＆gt; int和size 10。如何忽略其他无关数据？这是一个代码： / * $ i具有此数组的大小“$ tb_names”* /

 while ($i!=0){
                $result = mysql_query("SHOW COLUMNS FROM $tb_names[$j] ");
        if (!$result) {
            echo 'Could not run query: ' . mysql_error();
        exit;
        }
        if (mysql_num_rows($result) > 0) {
            while ($row = mysql_fetch_assoc($result)) {
            $var = print_r($row,true);
            echo $var."<br>";

        }
    }       
            $i--;
            $j++;


    }

Answer 1

您好，您可以试试query

SELECT column_name,character_maximum_length , data_type
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA =  'databasename'
AND TABLE_NAME =  'tablename';

针对特定列

SELECT column_name, character_maximum_length, data_type
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA =  'databasename'
AND TABLE_NAME =  'tablename'
AND column_name =  'columnname';

没有数据库名称

SELECT column_name , data_type ,character_maximum_length FROM information_schema.columns
WHERE table_name = 'tablename';

int长度请使用NUMERIC_PRECISION

SELECT column_name , data_type ,NUMERIC_PRECISION FROM information_schema.columns
    WHERE table_name = 'tablename';

Answer 2

你必须修改以适应你的用例，但尝试一下这个：

$allowedColumns = array(
    'columna',
    'columnb',
    'columnc',
    'columnd',
);

while( $i!=0 ) {
  $result = mysql_query("SHOW COLUMNS FROM $tb_names[$j] ");

  if( !$result ) {
    echo 'Could not run query: ' . mysql_error();
    exit;
  }
  if( mysql_num_rows($result) > 0 ) {
    while( $row = mysql_fetch_assoc($result) ) {
      $columns = array();
      foreach( $row as $column ) {
        if( in_array( $column, $allowedColumns ) ) {
          $columns[] = $column;
        }
      }
      $var = print_r($columns,true);
      echo $var."<br>";
    }
  }       
  $i--;
  $j++;
}

如何使用php

2 个答案: