PHP MySQL 在同一个表中复制一行...使用主键和唯一键

Question

My table has two keys, one is an auto incrementing id (PRIMARY), the other is the name of the item (UNIQUE).

Is it possible to duplicate a row within this same table? I have tried:

INSERT INTO items
SELECT * FROM items WHERE id = '9198'

This gives the error Duplicate entry '9198' for key 'PRIMARY'

I have also tried:

INSERT INTO items
SELECT * FROM items WHERE id = '9198'
ON DUPLICATE KEY UPDATE id=id+1

Which gives the error Column 'id' in field list is ambiguous

And as far as the item name (UNIQUE) field goes, is there a way to append (Copy) to the item name, since this field must also be unique?

Answer 1

Select all columns explicitly, except the id column:

INSERT INTO items
(col1, col2, ..., coln)
SELECT col1, col2, ..., coln
FROM items
WHERE id = '9198'

Your next question will probably be:

Is there a way to do this without listing all the columns explicitly?

Answer: No, I don't think so.

Answer 2

If you really don't want to list all the table columns like in Mark's answer, you can try this:

CREATE TEMPORARY TABLE temp_tbl SELECT * FROM items WHERE id = '9198';
SELECT @maxId := MAX(id) + 1 FROM items;
UPDATE temp_tbl SET id = @maxId;
INSERT INTO items SELECT * FROM temp_tbl;
DROP TABLE temp_tbl;

Not beautiful, not fast. But works.

Answer 3

Alternatively, if you don't want to write all the columns explicitly (and don't want to start creating/dropping tables), you can just get the columns of the table and build the query automagically:

//get the columns
$cols=array();
$result = mysql_query("SHOW COLUMNS FROM [table]"); 
 while ($r=mysql_fetch_assoc($result)) {
  if (!in_array($r["Field"],array("[unique key]"))) {//add other columns here to want to exclude from the insert
   $cols[]= $r["Field"];
  } //if
}//while

//build and do the insert       
$result = mysql_query("SELECT * FROM [table] WHERE [queries against want to duplicate]");
  while($r=mysql_fetch_array($result)) {
    $insertSQL = "INSERT INTO [table] (".implode(", ",$cols).") VALUES (";
    $count=count($cols);
    foreach($cols as $counter=>$col) {
      $insertSQL .= "'".$r[$col]."'";
  if ($counter<$count-1) {$insertSQL .= ", ";}//dont want a , on the last one
    }//foreach
  $insertSQL .= ")";

  mysql_query($insertSQL);//execute the query
  }//while

Note that this uses the depreciated code of MySQL and it should be MySQLi. I'm sure it could also be improved, but it's what I'm using and it works very well.

Answer 4

Thanks to hobailey for providing a great maintenance-free solution.

Here is the code I ended up using, which is updated for MySQLi:

// Get the columns
$cols = array();
$result = $mysqli->query("SHOW COLUMNS FROM [TABLE]"); // Change table name

while ($r = $result->fetch_array(MYSQLI_ASSOC)) {
    if (!in_array($r["Field"], array("COLA", "COL4", "COL8"))) { // Edit array with any column names you want to exclude
        $cols[] = $r["Field"];
    }
}

// Build and do the insert
$result = $mysqli->query("SELECT * FROM [TABLE] WHERE [SELECTION CRITERIA];"); // Change table name and add selection criteria

while ($r = $result->fetch_array(MYSQLI_ASSOC)) {

    $insertSQL = "INSERT INTO [TABLE] (" . implode(", ",$cols) . ") VALUES ("; // Change table name
    $count = count($cols);

    foreach($cols as $counter=>$col) {
// This is where you can add any code to change the value of existing columns
        $insertSQL .= "'" . $mysqli->real_escape_string($r[$col]) . "'";
        if ($counter < ($count - 1)) {
            $insertSQL .= ", ";
        }
    } // END foreach

    $insertSQL .= ");";

    $mysqli->query($insertSQL);
    if ($mysqli->affected_rows < 1) {
// Add code if the insert fails
    } else {
// Add code if the insert is successful
    }

} // END while

Answer 5

The question title does state you want to do this from PHP.

I've encountered the same problem and writing out all the column names is tedious and hard to maintain if you change your table structure (add/remove columns)... and I don't like the solutions that use temp tables.

I've elected to solve this problem with two queries sent from PHP - works great and no maintenance required (disclaimer: I use the meekrodb library for database access) :

//get the data as an associative array
$row = DB::queryFirstRow("SELECT * FROM your_table WHERE id=%i",$id);
if ($row){
    unset($row["id"]); //unset the primary key
    DB::insert("your_table",$row);
    return DB::insertId();
} else {
    return false;
}

You can even perform more manipulations on the internal data (unset other columns to ignore, edit values, etc) before re-inserting.

Answer 6

Another solution in PHP for copy a row in the same table without a specific column(s) / eg primary key - and without "TEMPORARY TABLE" and "SHOW COLUMNS FROM..."-method:

$stmt = $db->prepare("select * from table where id = :id;");
$stmt->bindValue(':id', $_GET['id'], PDO::PARAM_INT);
$stmt->execute();
$row = $stmt->fetch(PDO::FETCH_ASSOC);
unset($row['id']);      //remove primary key

$columns = array_keys($row);
$query = "insert into table (`".implode('`, `', $columns)."`) select `".implode('`, `', $columns)."` from  data_ticket_serie where id = ".$_GET['id'].";";
// echo $query;
$stmt = $db->prepare($query);
$stmt->execute();

The INSERT is a SELECT-statement, so the values are not direct in the statement --> no problems with "real_escape_string" or something like that.

Answer 7

For tables with many columns, I use a (yes, slow) method similar to Phius idea.
I put it here just for completeness.

Let's assume, table 'tbl' has an 'id' defined like

id INT NOT NULL AUTO_INCREMENT PRIMARY KEY

Then you can clone/copy a row by following these steps:

1. create a tmp table

CREATE TEMPORARY TABLE tbl_tmp LIKE tbl;

1. Insert one or more entries you want to clone / copy

INSERT INTO tbl_tmp SELECT * FROM tbl WHERE ...;

1. remove the AUTOINCREMENT tag from 'id'

ALTER TABLE tbl_tmp MODIFY id INT;

1. drop the primary index

ALTER TABLE tbl_tmp DROP PRIMARY KEY;

1. update your unique indices and set 'id' to 0 (0 needed for step 6. to work)

UPDATE tbl_tmp SET unique_value=?,id=0;

1. copy your modified rows into 'tbl' with 'id' being autogenerated.

INSERT INTO tbl SELECT * FROM tbl_tmp;

1. cleanup (or just close the DB connection)

DROP TABLE tbl_tmp;

If you also need clone/copy some dependant data in other tables, do the above for each row. After step 6 you can get the last inserted key and use this to clone/copy the dependant rows within other tables using the same procedure.

Answer 8

I am surprised anyone didn't mention using phpMyAdmin to create the query. Because this would make it fast to add all the columns and then you just set the id to null or o as mentioned above by wlf.

This is by far the simplest way to do it

INSERT INTO users SELECT 0,email,user FROM users WHERE id=10

Answer 9

I had to do something similar recently so I thought I post my solution for any size table, example included. It just take a configuration array which can be adjusted to practically any size table.

$copy_table_row = array(
    'table'=>'purchase_orders',     //table name
    'primary'=>'purchaseOrderID',   //primary key (or whatever column you're lookin up with index)
    'index'=>4084,                  //primary key index number
    'fields' => array(
        'siteID',             //copy colunm
        ['supplierID'=>21],   //overwrite this column to arbirary value by wrapping it in an array
        'status',             //copy colunm
        ['notes'=>'copied'],  //changes to "copied"
        'dateCreated',        //copy colunm
        'approved',           //copy colunm
    ),
);
echo copy_table_row($copy_table_row);



function copy_table_row($cfg){
    $d=[];
    foreach($cfg['fields'] as $i => $f){
        if(is_array($f)){
            $d['insert'][$i] = "`".current(array_keys($f))."`";
            $d['select'][$i] = "'".current($f)."'";
        }else{
            $d['insert'][$i] = "`".$f."`";
            $d['select'][$i] = "`".$f."`";
        }
    }
    $sql = "INSERT INTO `".$cfg['table']."` (".implode(', ',$d['insert']).")
        SELECT ".implode(',',$d['select'])."
        FROM `".$cfg['table']."`
        WHERE `".$cfg['primary']."` = '".$cfg['index']."';";
    return $sql;
}

This will output something like:

INSERT INTO `purchase_orders` (`siteID`, `supplierID`, `status`, `notes`, `dateCreated`, `approved`)
SELECT `siteID`,'21',`status`,'copied',`dateCreated`,`approved`
FROM `purchase_orders`
WHERE `purchaseOrderID` = '4084';

Answer 10

Simplest just make duplicate value of the record

INSERT INTO items (name,unit) SELECT name, unit FROM items WHERE id = '9198' 

Or With make duplicate the value of the record with add new/change value of some columns value like 'yes' or 'no'

INSERT INTO items (name,unit,is_variation) SELECT name, unit,'Yes' FROM items WHERE id = '9198' 

Answer 11

Say the table is user(id,email,user) and because you have a WHERE clause you can't use MAX(id)+1 :

INSERT INTO users SELECT 0,email,user FROM users WHERE id=10

Bear in mind though that you should always specify the column names when using INSERT.

Answer 12

I wanted to copy a row in my events table and found Mark's solution very helpful. I made it a bit shorter.

public static function getColumnsOfTable($table,  $arr_exclude_cols=array()) {
    global $obj_db;

    $cols = array();
    $result = $obj_db->query("SHOW COLUMNS FROM `".$table."`");

    while ($r = $result->fetch_array(MYSQLI_ASSOC)) {
        if (!in_array($r["Field"], $arr_exclude_cols)) { 
            $cols[] = $r["Field"];
        }
    }

    return $cols;
}

and the code for copying:

$cols = Utils::getColumnsOfTable('events', array('event_id'));

    $result1 = $obj_db->query('SELECT * FROM `events` WHERE `event_id` = '.$event_id);
    $arr_event = mysqli_fetch_array($result1, MYSQLI_NUM);
    unset($arr_event[0]);

    $insertSQL =  'INSERT INTO `events` (`' . implode('`, `',$cols) . '`) VALUES ("'. implode('","', $arr_event).'")'; 

Answer 13

This is a general function to copy an record of any table:

/**
 * @param string $table         Name of table
 * @param array $primaryKey     Which record should be copied? array('nameOfColumnWithUniqueId' => "value")
 * @param array $excludeFields  Which columns should not be copied (e.q. Unique Cols)
 * @param string $database      Name of database
 * @return int                  ID of new inserted record
 */
function copyMysqlRow($table, $primaryKey, $excludeFields = array(), $database = "usr_web3_2")
{
    $field = key($primaryKey);
    $value = current($primaryKey);
    $sql = "
        SELECT
            *
        FROM
            $database.$table
        WHERE
          $field = '$value'
    ";

    $result = mysql_query($sql);
    $row = mysql_fetch_assoc($result);

    $cols = array();
    $values = array();
    foreach ($row AS $col=>$value) {
        if (!in_array($col, $excludeFields)) {
            $cols[] = "`" . $col . "`";
            $values[] = $value === null ? 'null' : "'" . $value . "'";
        }
    }

    $sql = sprintf(" INSERT INTO $database.$table (%s) VALUES  (%s) ", implode($cols, ','), implode($values, ','));

    mysql_query($sql);

    return mysql_insert_id();
}

Answer 14

I use this one... it drops the primary key column on temp_tbl so there is no problem with duplicate IDs

CREATE TEMPORARY TABLE temp_tbl SELECT * FROM table_to_clone;
ALTER TABLE temp_tbl DROP COLUMN id;
INSERT INTO table_to_clone SELECT NULL, temp_tbl.* FROM temp_tbl;
DROP TABLE temp_tbl;

Answer 15

Since tables can often have DEFAULT values (create_date etc), it is useful to go with field names, a function like this will work in mysql, postge and mssql.

function duplicate_row($table, $id, $fields) {
global $conn;
try {
    $query = "SELECT * FROM $table WHERE id = :id";
    $stmt = $conn->prepare($query);
    $stmt->bindValue(":id", $id);
    $stmt->execute();
    $row = $stmt->fetch(PDO::FETCH_ASSOC);
    $query = "INSERT INTO $table (" . implode(", ", $fields) . ") VALUES (:" . implode(", :", $fields) . ")";
    $stmt = $conn->prepare($query);
    foreach ($fields as $key) {
        $stmt->bindValue(":" . $key, $row[$key]);
    }
    $stmt->execute();
    return $conn->lastInsertId();
} catch (PDOException $e) {
    echo "Error: " . $e->getMessage();
}}

If you give the field names in an array, it will return the id it copied.

$dup_id = duplicate_row("table1", 9198, Array("field1","field2"));
echo $dup_id;