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Get table column names in MySQL?

开发者 https://www.devze.com 2022-12-08 00:33 出处:网络
Is there a way to grab the column开发者_如何转开发s name of a table in MySQL using PHP?You can use DESCRIBE:

Is there a way to grab the column开发者_如何转开发s name of a table in MySQL using PHP?


You can use DESCRIBE:

DESCRIBE my_table;

Or in newer versions you can use INFORMATION_SCHEMA:

SELECT COLUMN_NAME
  FROM INFORMATION_SCHEMA.COLUMNS
  WHERE TABLE_SCHEMA = 'my_database' AND TABLE_NAME = 'my_table';

Or you can use SHOW COLUMNS:

SHOW COLUMNS FROM my_table;

Or to get column names with comma in a line:

SELECT group_concat(COLUMN_NAME)
  FROM INFORMATION_SCHEMA.COLUMNS
  WHERE TABLE_SCHEMA = 'my_database' AND TABLE_NAME = 'my_table';


The following SQL statements are nearly equivalent:

SELECT COLUMN_NAME
  FROM INFORMATION_SCHEMA.COLUMNS
 WHERE table_name = 'tbl_name'
  [AND table_schema = 'db_name']
  [AND column_name LIKE 'wild']

SHOW COLUMNS
FROM tbl_name
[FROM db_name]
[LIKE 'wild']

Reference: INFORMATION_SCHEMA COLUMNS


I made a PDO function which returns all the column names in an simple array.

public function getColumnNames($table){
    $sql = "SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name = :table";
    try {
        $core = Core::getInstance();
        $stmt = $core->dbh->prepare($sql);
        $stmt->bindValue(':table', $table, PDO::PARAM_STR);
        $stmt->execute();
        $output = array();
        while($row = $stmt->fetch(PDO::FETCH_ASSOC)){
            $output[] = $row['COLUMN_NAME'];                
        }
        return $output; 
    }

    catch(PDOException $pe) {
        trigger_error('Could not connect to MySQL database. ' . $pe->getMessage() , E_USER_ERROR);
    }
}

The output will be an array:

Array (
[0] => id
[1] => name
[2] => email
[3] => shoe_size
[4] => likes
... )

Sorry for the necro but I like my function ;)

P.S. I have not included the class Core but you can use your own class.. D.S.


There's also this if you prefer:

mysql_query('SHOW COLUMNS FROM tableName'); 


This solution is from command line mysql

mysql>USE information_schema;

In below query just change <--DATABASE_NAME--> to your database and <--TABLENAME--> to your table name where you just want Field values of DESCRIBE statement

mysql> SELECT COLUMN_NAME FROM COLUMNS WHERE TABLE_SCHEMA = '<--DATABASE_NAME-->' AND   TABLE_NAME='<--TABLENAME-->';


I needed column names as a flat array, while the other answers returned associative arrays, so I used:

$con = mysqli_connect('localhost',$db_user,$db_pw,$db_name);
$table = 'people';

/**
* Get the column names for a mysql table
**/

function get_column_names($con, $table) {
  $sql = 'DESCRIBE '.$table;
  $result = mysqli_query($con, $sql);

  $rows = array();
  while($row = mysqli_fetch_assoc($result)) {
    $rows[] = $row['Field'];
  }

  return $rows;
}

$col_names = function get_column_names($con, $table);

$col_names now equals:

(
    [0] => name
    [1] => parent
    [2] => number
    [3] => chart_id
    [4] => type
    [5] => id
)


It's also interesting to note that you can use
EXPLAIN table_name which is synonymous with DESCRIBE table_name and SHOW COLUMNS FROM table_name although EXPLAIN is more commonly used to obtain information about the query execution plan.


How about this:

SELECT @cCommand := GROUP_CONCAT( COLUMN_NAME ORDER BY column_name SEPARATOR ',\n')
FROM INFORMATION_SCHEMA.COLUMNS 
WHERE TABLE_SCHEMA = 'my_database' AND TABLE_NAME = 'my_table';

SET @cCommand = CONCAT( 'SELECT ', @cCommand, ' from my_database.my_table;');
PREPARE xCommand from @cCommand;
EXECUTE xCommand;


Look into:

mysql_query('DESCRIBE '.$table);


The MySQL function describe table should get you where you want to go (put your table name in for "table"). You'll have to parse the output some, but it's pretty easy. As I recall, if you execute that query, the PHP query result accessing functions that would normally give you a key-value pair will have the column names as the keys. But it's been a while since I used PHP so don't hold me to that. :)


The mysql_list_fields function might interest you ; but, as the manual states :

This function is deprecated. It is preferable to use mysql_query() to issue a SQL SHOW COLUMNS FROM table [LIKE 'name'] statement instead.


You may also want to check out mysql_fetch_array(), as in:

$rs = mysql_query($sql);
while ($row = mysql_fetch_array($rs)) {
//$row[0] = 'First Field';
//$row['first_field'] = 'First Field';
}


in mysql to get columns details and table structure by following keywords or queries

1.DESC table_name

2.DESCRIBE table_name

3.SHOW COLUMNS FROM table_name

4.SHOW create table table_name;

5.EXPLAIN table_name


you can get the entire table structure using following simple command.

DESC TableName

or you can use following query.

SHOW COLUMNS FROM TableName


$col = $db->query("SHOW COLUMNS FROM category");

while ($fildss = $col->fetch_array())
{             
    $filds[] = '"{'.$fildss['Field'].'}"';
    $values[] = '$rows->'.$fildss['Field'].'';
}

if($type == 'value')
{
    return $values = implode(',', $values);
}
else {
     return $filds = implode(',', $filds);
}


this worked for me..

$sql = "desc MyTableName";
$result = @mysql_query($sql);
while($row = @mysql_fetch_array($result)){
    echo $row[0]."<br>";
}


I have write a simple php script to fetch table columns through PHP: Show_table_columns.php

<?php
$db = 'Database'; //Database name
$host = 'Database_host'; //Hostname or Server ip
$user = 'USER'; //Database user
$pass = 'Password'; //Database user password
$con = mysql_connect($host, $user, $pass);
if ($con) {
    $link = mysql_select_db($db) or die("no database") . mysql_error();
    $count = 0;
    if ($link) {
        $sql = "
            SELECT column_name
            FROM   information_schema.columns
            WHERE  table_schema = '$db'
                   AND table_name = 'table_name'"; // Change the table_name your own table name
        $result = mysql_query($sql, $con);
        if (mysql_query($sql, $con)) {
            echo $sql . "<br> <br>";
            while ($row = mysql_fetch_row($result)) {
                echo "COLUMN " . ++$count . ": {$row[0]}<br>";
                $table_name = $row[0];
            }
            echo "<br>Total No. of COLUMNS: " . $count;
        } else {
            echo "Error in query.";
        }
    } else {
        echo "Database not found.";
    }
} else {
    echo "Connection Failed.";
}
?>

Enjoy!


mysqli fetch_field() worked for me:

if ($result = $mysqli -> query($sql)) {
  // Get field information for all fields
  while ($fieldinfo = $result -> fetch_field()) {
    printf("Name: %s\n", $fieldinfo -> name);
    printf("Table: %s\n", $fieldinfo -> table);
    printf("Max. Len: %d\n", $fieldinfo -> max_length);
  }
  $result -> free_result();
}

Source: https://www.w3schools.com/pHP/func_mysqli_fetch_field.asp


The easy way, if loading results using assoc is to do this:

$sql = "SELECT p.* FROM (SELECT 1) as dummy LEFT JOIN `product_table` p on null";
$q = $this->db->query($sql);
$column_names = array_keys($q->row);

This you load a single result using this query, you get an array with the table column names as keys and null as value. E.g.

Array(
'product_id' => null,
'sku' => null,
'price' => null,
...
)

after which you can easily get the table column names using the php function array_keys($result)

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