When I run the code below when $entry = miami.com, I get the following error message:
SELECT COUNT(*) FROM #&*+ WHERE `site`
LIKE 'miami.com':You have an error in
your SQL syntax; check the manual that
corresponds to your MySQL server
version for the right syntax to use
near '' at line 1
It looks like I'm not correctly defining $table. Any ideas how I could do that?
Thanks in advance,
John
$result = mysql_query("SHOW TABLES FROM feather")
or die(mysql_error());
while(list($table)= mysql_fetch_row($result))
{
$sqlA = "SELECT COUNT(*) FROM $table WHERE `site` LIKE '$entry'";
$resA = mysql_query($sqlA) or die("$sqlA:".mysql_error());
list($isThere) = mysql_fetch_row($resA);
if ($isThere)
{
$table_list[] = $table;
}
}
if it were me debugging that i would see what
print_r(mysql_fetch_row($result));
outputs
I think you are using the list-language construct incorrectly:
Description
void list ( mixed $varname [, mixed $... ] )
Like array(), this is not really a function, but a language construct. list() is used to > assign a list of variables in one operation.
Example:
$info = array('coffee', 'brown', 'caffeine');
// Listing all the variables
list($drink, $color, $power) = $info;
echo "$drink is $color and $power makes it special.\n";
Now, what you are trying to do is to fetch dynamic table-names (it seems). You do not need to use the list-function, since you can access the result as an array (you can define the appropriate indexes of the array that you are interested in and only assign them, but I think array access is much clearer):
while($row = mysql_fetch_assoc($result))
{
$sqlA = "SELECT COUNT(*) FROM ${row['table']} WHERE `site` LIKE '$entry'";
[...]
}
I am a bit curious though, do ALL the tables in your database feather have a column named site? Otherwise this query will fail, no matter how you format or refactor your code.
Actually, I recently recalled that my
very first table name is indeed
"#&*+." I added it deliberately during
development
And you're wondering why your SQL fails? :)
Quote your table name because this one is by far not a table name that can be used literally.
Something like
"SELECT COUNT(*) FROM \"$table\" ...
i think need to add MYSQL_ASSOC
to line that do the loop
mysql_fetch_row($result,MYSQL_ASSOC)
the default is : MYSQL_BOTH
what mean that in the php loop you get the entry of the table name ,
and the entry of index like 0,1,2,...
I am pretty sure your SHOW TABLES query is returning garbage. I was able to reproduce your problem by copying an existing table_name.frm to #&#.frm in the data folder for a local database. Make sure your database is not corrupt (meaning, try repair): http://dev.mysql.com/doc/refman/5.1/en/repair-table.html
I think this is what you're after:
$result = mysql_query("SHOW TABLES FROM feather") or die(mysql_error());
while($table_row = mysql_fetch_row($result))
{
$table = $table_row[0];
$sqlA = "SELECT COUNT(*) FROM `" . mysql_escape_string($table) . "` WHERE `site` LIKE '" . mysql_escape_string($entry) . "'";
$resA = mysql_query($sqlA) or die("$sqlA:".mysql_error());
$isThere_row = mysql_fetch_row($resA);
$isThere = $isThere_row[0];
if ($isThere)
{
$table_list[] = $table;
}
}
NOTE: variables inside your sql should be escaped. I don't use mySQL but I assume mysql_escape_string should work. There is another function, mysql_real_escape_string, that might be more appropropriate. You may want to read the docs for that.
Related
I'd like to get all of a mysql table's col names into an array in php?
Is there a query for this?
The best way is to use the INFORMATION_SCHEMA metadata virtual database. Specifically the INFORMATION_SCHEMA.COLUMNS table...
SELECT `COLUMN_NAME`
FROM `INFORMATION_SCHEMA`.`COLUMNS`
WHERE `TABLE_SCHEMA`='yourdatabasename'
AND `TABLE_NAME`='yourtablename';
It's VERY powerful, and can give you TONS of information without need to parse text (Such as column type, whether the column is nullable, max column size, character set, etc)...
Oh, and it's standard SQL (Whereas SHOW ... is a MySQL specific extension)...
For more information about the difference between SHOW... and using the INFORMATION_SCHEMA tables, check out the MySQL Documentation on INFORMATION_SCHEMA in general...
You can use the following query for MYSQL:
SHOW `columns` FROM `your-table`;
Below is the example code which shows How to implement above syntax in php to list the names of columns:
$sql = "SHOW COLUMNS FROM your-table";
$result = mysqli_query($conn,$sql);
while($row = mysqli_fetch_array($result)){
echo $row['Field']."<br>";
}
For Details about output of SHOW COLUMNS FROM TABLE visit: MySQL Refrence.
Seems there are 2 ways:
DESCRIBE `tablename`
or
SHOW COLUMNS FROM `tablename`
More on DESCRIBE here: http://dev.mysql.com/doc/refman/5.0/en/describe.html
I have done this in the past.
SELECT column_name
FROM information_schema.columns
WHERE table_name='insert table name here';
Edit: Today I learned the better way of doing this. Please see ircmaxell's answer.
Parse the output of SHOW COLUMNS FROM table;
Here's more about it here: http://dev.mysql.com/doc/refman/5.0/en/show-columns.html
Use mysql_fetch_field() to view all column data. See manual.
$query = 'select * from myfield';
$result = mysql_query($query);
$i = 0;
while ($i < mysql_num_fields($result))
{
$fld = mysql_fetch_field($result, $i);
$myarray[]=$fld->name;
$i = $i + 1;
}
"Warning
This extension is deprecated as of PHP 5.5.0, and will be removed in the future."
The simplest solution out of all Answers:
DESC `table name`
or
DESCRIBE `table name`
or
SHOW COLUMNS FROM `table name`
An old PHP function "mysql_list_fields()" is deprecated. So, today the best way to get names of fields is a query "SHOW COLUMNS FROM table_name [LIKE 'name']". So, here is a little example:
$fields = array();
$res=mysql_query("SHOW COLUMNS FROM mytable");
while ($x = mysql_fetch_assoc($res)){
$fields[] = $x['Field'];
}
foreach ($fields as $f) { echo "<br>Field name: ".$f; }
when you want to check your all table structure with some filed then use this code. In this query i select column_name,column_type and table_name for more details . I use order by column_type so i can see it easily.
SELECT `COLUMN_NAME`,COLUMN_TYPE,TABLE_NAME
FROM `INFORMATION_SCHEMA`.`COLUMNS`
WHERE `TABLE_SCHEMA`='yourdatabasename' order by DATA_TYPE;
If you want to check only double type filed then you can do it easily
SELECT `COLUMN_NAME`,COLUMN_TYPE,TABLE_NAME,DATA_TYPE
FROM `INFORMATION_SCHEMA`.`COLUMNS`
WHERE `TABLE_SCHEMA`='yourdatabasename' AND DATA_TYPE like '%bigint%' order by DATA_TYPE;
if you want to check which field allow null type etc then you can use this
SELECT `COLUMN_NAME`,COLUMN_TYPE,TABLE_NAME,IS_NULLABLE,DATA_TYPE
FROM `INFORMATION_SCHEMA`.`COLUMNS`
WHERE `TABLE_SCHEMA`='yourdatabasename' and DATA_TYPE like '%bigint%' and IS_NULLABLE ='NO' order by COLUMN_TYPE;
you want to check more then thik link also help you.
https://dev.mysql.com/doc/refman/5.7/en/columns-table.html
this generates a string of column names with a comma delimiter:
SELECT CONCAT('(',GROUP_CONCAT(`COLUMN_NAME`),')')
FROM `INFORMATION_SCHEMA`.`COLUMNS`
WHERE `TABLE_SCHEMA`='database_name'
AND `TABLE_NAME`='table_name';
function get_col_names(){
$sql = "SHOW COLUMNS FROM tableName";
$result = mysql_query($sql);
while($record = mysql_fetch_array($result)){
$fields[] = $record['0'];
}
foreach ($fields as $value){
echo 'column name is : '.$value.'-';
}
}
return get_col_names();
Not sure if this is what you were looking for, but this worked for me:
$query = query("DESC YourTable");
$col_names = array_column($query, 'Field');
That returns a simple array of the column names / variable names in your table or array as strings, which is what I needed to dynamically build MySQL queries. My frustration was that I simply don't know how to index arrays in PHP very well, so I wasn't sure what to do with the results from DESC or SHOW. Hope my answer is helpful to beginners like myself!
To check result: print_r($col_names);
SHOW COLUMNS in mysql 5.1 (not 5.5) uses a temporary disk table.
http://dev.mysql.com/doc/refman/5.1/en/internal-temporary-tables.html
http://dev.mysql.com/doc/refman/5.1/en/show-columns.html
So it can be considered slow for some cases. At least, it can bump up your created_tmp_disk_tables value. Imagine one temporary disk table per connection or per each page request.
SHOW COLUMNS is not really so slow, possibly because it uses file system cache. Phpmyadmin says ~0.5ms consistently. This is nothing compared to 500ms-1000ms of serving a wordpress page. But still, there are times it matters. There is a disk system involvement, you never know what happens when server is busy, cache is full, hdd is stalled etc.
Retrieving column names through SELECT * FROM ... LIMIT 1 was around ~0.1ms, and it can use query cache as well.
So here is my little optimized code to get column names from a table, without using show columns if possible:
function db_columns_ar($table)
{
//returns Array('col1name'=>'col1name','col2name'=>'col2name',...)
if(!$table) return Array();
if(!is_string($table)) return Array();
global $db_columns_ar_cache;
if(!empty($db_columns_ar_cache[$table]))
return $db_columns_ar_cache[$table];
//IMPORTANT show columns creates a temp disk table
$cols=Array();
$row=db_row_ar($q1="SELECT * FROM `$table` LIMIT 1");
if($row)
{
foreach($row as $name=>$val)
$cols[$name]=$name;
}
else
{
$coldata=db_rows($q2="SHOW COLUMNS FROM `$table`");
if($coldata)
foreach($coldata as $row)
$cols[$row->Field]=$row->Field;
}
$db_columns_ar_cache[$table]=$cols;
//debugexit($q1,$q2,$row,$coldata,$cols);
return $cols;
}
Notes:
As long as your tables first row does not contain megabyte range of data, it should work fine.
The function names db_rows and db_row_ar should be replaced with your specific database setup.
IN WORDPRESS:
global $wpdb; $table_name=$wpdb->prefix.'posts';
foreach ( $wpdb->get_col( "DESC " . $table_name, 0 ) as $column_name ) {
var_dump( $column_name );
}
Try this one out I personally use it:
SHOW COLUMNS FROM $table where field REGEXP 'stock_id|drug_name'
This question is old, but I got here looking for a way to find a given query its field names in a dynamic way (not necessarily only the fields of a table). And since people keep pointing this as the answer for that given task in other related questions, I'm sharing the way I found it can be done, using Gavin Simpson's tips:
//Function to generate a HTML table from a SQL query
function myTable($obConn,$sql)
{
$rsResult = mysqli_query($obConn, $sql) or die(mysqli_error($obConn));
if(mysqli_num_rows($rsResult)>0)
{
//We start with header. >>>Here we retrieve the field names<<<
echo "<table width=\"100%\" border=\"0\" cellspacing=\"2\" cellpadding=\"0\"><tr align=\"center\" bgcolor=\"#CCCCCC\">";
$i = 0;
while ($i < mysqli_num_fields($rsResult)){
$field = mysqli_fetch_field_direct($rsResult, $i);
$fieldName=$field->name;
echo "<td><strong>$fieldName</strong></td>";
$i = $i + 1;
}
echo "</tr>";
//>>>Field names retrieved<<<
//We dump info
$bolWhite=true;
while ($row = mysqli_fetch_assoc($rsResult)) {
echo $bolWhite ? "<tr bgcolor=\"#CCCCCC\">" : "<tr bgcolor=\"#FFF\">";
$bolWhite=!$bolWhite;
foreach($row as $data) {
echo "<td>$data</td>";
}
echo "</tr>";
}
echo "</table>";
}
}
This can be easily modded to insert the field names in an array.
Using a simple: $sql="SELECT * FROM myTable LIMIT 1" can give you the fields of any table, without needing to use SHOW COLUMNS or any extra php module, if needed (removing the data dump part).
Hopefully this helps someone else.
if you use php, use this gist.
it can get select fields full info with no result，and all custom fields such as:
SELECT a.name aname, b.name bname, b.*
FROM table1 a LEFT JOIN table2 b
ON a.id = b.pid;
if above sql return no data,will also get the field names aname, bname, b's other field name
just two line:
$query_info = mysqli_query($link, $data_source);
$fetch_fields_result = $query_info->fetch_fields();
This query fetches a list of all columns in a database without having to specify a table name. It returns a list of only column names:
SELECT COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_schema = 'db_name'
However, when I ran this query in phpmyadmin, it displayed a series of errors. Nonetheless, it worked. So use it with caution.
if you only need the field names and types (perhaps for easy copy-pasting into Excel):
SELECT COLUMN_NAME, DATA_TYPE
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA='databasenamegoeshere'
AND DATA_TYPE='decimal' and TABLE_NAME = 'tablenamegoeshere'
remove
DATA_TYPE='decimal'
if you want all data types
i no expert, but this works for me..
$sql = "desc MyTable";
$result = #mysql_query($sql);
while($row = #mysql_fetch_array($result)){
echo $row[0]."<br>"; // returns the first column of array. in this case Field
// the below code will return a full array-> Field,Type,Null,Key,Default,Extra
// for ($c=0;$c<sizeof($row);$c++){echo #$row[$c]."<br>";}
}
I have tried this query in SQL Server and this worked for me :
SELECT name FROM sys.columns WHERE OBJECT_ID = OBJECT_ID('table_name')
The call of DESCRIBE is working fine to get all columns of a table but if you need to filter on it, you need to use the SHOW COLUMNS FROM instead.
Example of PHP function to get all info of a table :
// get table columns (or return false if table not found)
function get_table_columns($db, $table) {
global $pdo;
if($cols = $pdo->query("DESCRIBE `$db`.`$table`")) {
if($cols = $cols->fetchAll(PDO::FETCH_ASSOC)) {
return $cols;
}
}
return false;
}
In my case, I had to find the primary key of a table. So, I used :
SHOW COLUMNS FROM `table` WHERE `Key`='PRI';
Here is my PHP function :
// get table Primary Key
function get_table_pk($db, $table) {
global $pdo;
$q = "SHOW COLUMNS FROM `$db`.`$table` WHERE `Key` = 'PRI'";
if($cols = $pdo->query($q)) {
if($cols = $cols->fetchAll(PDO::FETCH_ASSOC)) {
return $cols[0];
}
}
return false;
}
So I'm trying to use a "LIKE" in the SQL, basically to see if a player is in a team already. Here's the code I have:
$checkifonlytwo = "SELECT * FROM sg_turn_teams WHERE joinid = :joinid AND players LIKE '%:ownerid,%'";
$paramstwo = array(
":joinid" => $joinid,
":ownerid" => $_SESSION['user']['id']
);
try{
$stmttwo = $db->prepare($checkifonlytwo);
$resulttwo = $stmttwo->execute($paramstwo);
}
catch(PDOException $ex){
die("Failed to run query #2: " . $ex->getMessage());
}
Also as you can see I want it to be LIKE '%1,%' for example, so the comma at the end too.
My table structure looks like this.
EDIT, the players is going to be like "1,2,3" without the names because the users are able to change their name. The picture is with names, but it's supposed to be 1,2,3
Foreword. I decided to make this a community wiki. I did not want to gain anything from this, except for the OP and others visiting the question.
As I said in comments, you're going about it the wrong way with the comma in there ownerid,.
What you need to do is implode on the array and using IN().
Borrowed from https://stackoverflow.com/a/12151295/
$e = 0;
while($e<$num1){
$units = 0;
$r = 0;
$SO_Line_Item=mysql_result($result1,$e,"SO_Line_Item");
foreach ($Boxes[$e] as $a => $b)
{
$zzz[] = $Boxes[$e][$r];
$ce = count($Boxes[$e]);
$r++;
}
//end inner foreach
$products = implode(',', array_fill(0,$ce, '?'));
$db = new PDO('mysql:host=192.168.1.197 ;dbname=Tracking', $dbuser,$dbpass);
$stmt = $db->prepare("SELECT Box_Num,Timestamp,E3_SN,Assy_Status FROM Current_Box WHERE Box_Num IN( $products )");
$stmt->execute($zzz);
$results = $stmt->fetchAll(PDO::FETCH_ASSOC);
}
unset($zzz);
$e++;
}
and from https://stackoverflow.com/a/2814703/
$ids = array(2, 4, 6, 8);
// prepare a string that contains ":id_0,..,:id_n" and include it in the SQL
$plist = ':id_'.implode(',:id_', array_keys($ids));
$sql = "SELECT * FROM someTable WHERE someId IN ($plist)";
// prepare & execute the actual statement
$parms = array_combine(explode(",", $plist), $ids);
$stmt = $PDO->prepare($sql);
$rows = $stmt->execute($parms);
From comments:
"You might want to use association tables rather than storing the information the way you are storing it. – Maximus2012"
As mentioned in the comments, some questions/answers from SO that demonstrate the concept of Association tables along with composite primary keys:
Mysql : Association table
How to use an MySQL association table to return categories not currently assigned to an entry
If OP decides to go with this structure then the queries would need to be changed to make use of LEFT JOIN and/or use a sub-query with IN clause. There are plenty of examples of both on SO. One that I could find with a simple search (please ignore the slow query part and look at the examples to demonstrate the concept):
MySQL - SELECT WHERE field IN (subquery) - Extremely slow why?
For the user I am testing with, their org_id column value is "student_life"
I am trying to have this function display whatever rows have the student_life column = 1. (so yes there is a column student_life which is a boolean, and then I also have a separate column named org_id and in this case has the value student_life)
I am pretty sure there is a syntax error but I cannot figure it out.
function org_id_users_table()
{
$org_id = mysql_real_escape_string($_POST["org_id"]);
$sql = $this->query("SELECT * FROM ".DBTBLE." WHERE '$org_id' = '1'");
$result = $sql['sql'];
$num_rows = $sql['num_rows'];
$this->create_table($result, $num_rows);
}
(when I replace $org_id in the "$sql=..." line with student_life the code works.
You're quoting the column name, which makes MySQL think it's a string.
$sql = $this->query("SELECT * FROM ".DBTBLE." WHERE $org_id = '1'");
Edit:
Based on your comments, I think what you actually want is this:
$sql = $this->query("SELECT * FROM ".DBTBLE." WHERE org_id = '$org_id'");
Change quotes.
$sql = $this->query("SELECT * FROM ".DBTBLE." WHERE `$org_id` = '1'");
P.S. Why shouldn't I use mysql_* functions in PHP?
Where is this coming from? $_POST["org_id"]
Do you have a form on the page posting that? Or are you just trying to get that from the database? If so, wouldn't you need another query to obtain that first?
$row_MyFirstQuery['org_id']
Otherwise if it is $_POST["org_id"], wouldn't it be single quotes not double? $_POST['org_id']
I'm afraid this is going to sound redundant. I have done my diligence, and substituted at least three ideas I've found so far, and nothing works.
The goal is to merge unique fields from two tables, but right now I can't even get identical fields from one table into another that was created as an identical table. Here is the code so far, with my comments:
$result = mysql_query("SELECT * from $db.$tbl LIMIT 50");
if($result) {
while($maindata = mysql_fetch_assoc($result)) {
$newdata = implode ("," , $maindata);
$newdata = mysql_escape_string($newdata);
$pop = "INSERT INTO $db.address_new (id,entitynum,address,city,state,zip,country,remarks)
SELECT FROM $db.address";
//This is the original code replaced by the above
//$pop = "INSERT INTO $db.address_new (id,entitynum,address,city,state,zip,country,remarks)
// VALUES ($newdata)";
mysql_query($pop);
//print_r($pop);
//Seems to give the correct output in the browser, but the table address_new remains empty. `
Thank you in advance. I really appreciate your help.
To directly insert from another table (note: if ID is auto_increment you may or may not want to insert it this way):
INSERT INTO db.address_new (id,entitynum,address,city,state,zip,country,remarks)
SELECT (id,entitynum,address,city,state,zip,country,remarks)
FROM db.address LIMIT 50
(do not put this in a loop)
If you're looking for unique values, you can do that a couple of ways. Personally, I would have a unique key on one (or a set of) the values and then just do INSERT IGNORE:
INSERT IGNORE INTO db.address_new
(id,entitynum,address,city,state,zip,country,remarks)
SELECT (id,entitynum,address,city,state,zip,country,remarks)
FROM db.address LIMIT 50
As a side note:
// use mysql_real_escape_string
mysql_escape_string($newdata);
// since you're passing this through PHP, you need to make sure to quote
// all of your values. This probably means you'll need to loop and replace this
// $newdata = implode ("," , $maindata);
// with something like:
$newdata = array();
foreach( $maindata as $column )
{
$newdata[] = "'" . mysql_real_escape_string( $column ) . "'";
}
$newdata = implode(',', $newdata);
// you're missing the columns in your select clause.
$pop = "INSERT INTO $db.address_new ".
"(id,entitynum,address,city,state,zip,country,remarks) ".
// You need to select *something*
"SELECT FROM $db.address";
I'd like to get all of a mysql table's col names into an array in php?
Is there a query for this?
The best way is to use the INFORMATION_SCHEMA metadata virtual database. Specifically the INFORMATION_SCHEMA.COLUMNS table...
SELECT `COLUMN_NAME`
FROM `INFORMATION_SCHEMA`.`COLUMNS`
WHERE `TABLE_SCHEMA`='yourdatabasename'
AND `TABLE_NAME`='yourtablename';
It's VERY powerful, and can give you TONS of information without need to parse text (Such as column type, whether the column is nullable, max column size, character set, etc)...
Oh, and it's standard SQL (Whereas SHOW ... is a MySQL specific extension)...
For more information about the difference between SHOW... and using the INFORMATION_SCHEMA tables, check out the MySQL Documentation on INFORMATION_SCHEMA in general...
You can use the following query for MYSQL:
SHOW `columns` FROM `your-table`;
Below is the example code which shows How to implement above syntax in php to list the names of columns:
$sql = "SHOW COLUMNS FROM your-table";
$result = mysqli_query($conn,$sql);
while($row = mysqli_fetch_array($result)){
echo $row['Field']."<br>";
}
For Details about output of SHOW COLUMNS FROM TABLE visit: MySQL Refrence.
Seems there are 2 ways:
DESCRIBE `tablename`
or
SHOW COLUMNS FROM `tablename`
More on DESCRIBE here: http://dev.mysql.com/doc/refman/5.0/en/describe.html
I have done this in the past.
SELECT column_name
FROM information_schema.columns
WHERE table_name='insert table name here';
Edit: Today I learned the better way of doing this. Please see ircmaxell's answer.
Parse the output of SHOW COLUMNS FROM table;
Here's more about it here: http://dev.mysql.com/doc/refman/5.0/en/show-columns.html
Use mysql_fetch_field() to view all column data. See manual.
$query = 'select * from myfield';
$result = mysql_query($query);
$i = 0;
while ($i < mysql_num_fields($result))
{
$fld = mysql_fetch_field($result, $i);
$myarray[]=$fld->name;
$i = $i + 1;
}
"Warning
This extension is deprecated as of PHP 5.5.0, and will be removed in the future."
The simplest solution out of all Answers:
DESC `table name`
or
DESCRIBE `table name`
or
SHOW COLUMNS FROM `table name`
An old PHP function "mysql_list_fields()" is deprecated. So, today the best way to get names of fields is a query "SHOW COLUMNS FROM table_name [LIKE 'name']". So, here is a little example:
$fields = array();
$res=mysql_query("SHOW COLUMNS FROM mytable");
while ($x = mysql_fetch_assoc($res)){
$fields[] = $x['Field'];
}
foreach ($fields as $f) { echo "<br>Field name: ".$f; }
when you want to check your all table structure with some filed then use this code. In this query i select column_name,column_type and table_name for more details . I use order by column_type so i can see it easily.
SELECT `COLUMN_NAME`,COLUMN_TYPE,TABLE_NAME
FROM `INFORMATION_SCHEMA`.`COLUMNS`
WHERE `TABLE_SCHEMA`='yourdatabasename' order by DATA_TYPE;
If you want to check only double type filed then you can do it easily
SELECT `COLUMN_NAME`,COLUMN_TYPE,TABLE_NAME,DATA_TYPE
FROM `INFORMATION_SCHEMA`.`COLUMNS`
WHERE `TABLE_SCHEMA`='yourdatabasename' AND DATA_TYPE like '%bigint%' order by DATA_TYPE;
if you want to check which field allow null type etc then you can use this
SELECT `COLUMN_NAME`,COLUMN_TYPE,TABLE_NAME,IS_NULLABLE,DATA_TYPE
FROM `INFORMATION_SCHEMA`.`COLUMNS`
WHERE `TABLE_SCHEMA`='yourdatabasename' and DATA_TYPE like '%bigint%' and IS_NULLABLE ='NO' order by COLUMN_TYPE;
you want to check more then thik link also help you.
https://dev.mysql.com/doc/refman/5.7/en/columns-table.html
this generates a string of column names with a comma delimiter:
SELECT CONCAT('(',GROUP_CONCAT(`COLUMN_NAME`),')')
FROM `INFORMATION_SCHEMA`.`COLUMNS`
WHERE `TABLE_SCHEMA`='database_name'
AND `TABLE_NAME`='table_name';
function get_col_names(){
$sql = "SHOW COLUMNS FROM tableName";
$result = mysql_query($sql);
while($record = mysql_fetch_array($result)){
$fields[] = $record['0'];
}
foreach ($fields as $value){
echo 'column name is : '.$value.'-';
}
}
return get_col_names();
Not sure if this is what you were looking for, but this worked for me:
$query = query("DESC YourTable");
$col_names = array_column($query, 'Field');
That returns a simple array of the column names / variable names in your table or array as strings, which is what I needed to dynamically build MySQL queries. My frustration was that I simply don't know how to index arrays in PHP very well, so I wasn't sure what to do with the results from DESC or SHOW. Hope my answer is helpful to beginners like myself!
To check result: print_r($col_names);
SHOW COLUMNS in mysql 5.1 (not 5.5) uses a temporary disk table.
http://dev.mysql.com/doc/refman/5.1/en/internal-temporary-tables.html
http://dev.mysql.com/doc/refman/5.1/en/show-columns.html
So it can be considered slow for some cases. At least, it can bump up your created_tmp_disk_tables value. Imagine one temporary disk table per connection or per each page request.
SHOW COLUMNS is not really so slow, possibly because it uses file system cache. Phpmyadmin says ~0.5ms consistently. This is nothing compared to 500ms-1000ms of serving a wordpress page. But still, there are times it matters. There is a disk system involvement, you never know what happens when server is busy, cache is full, hdd is stalled etc.
Retrieving column names through SELECT * FROM ... LIMIT 1 was around ~0.1ms, and it can use query cache as well.
So here is my little optimized code to get column names from a table, without using show columns if possible:
function db_columns_ar($table)
{
//returns Array('col1name'=>'col1name','col2name'=>'col2name',...)
if(!$table) return Array();
if(!is_string($table)) return Array();
global $db_columns_ar_cache;
if(!empty($db_columns_ar_cache[$table]))
return $db_columns_ar_cache[$table];
//IMPORTANT show columns creates a temp disk table
$cols=Array();
$row=db_row_ar($q1="SELECT * FROM `$table` LIMIT 1");
if($row)
{
foreach($row as $name=>$val)
$cols[$name]=$name;
}
else
{
$coldata=db_rows($q2="SHOW COLUMNS FROM `$table`");
if($coldata)
foreach($coldata as $row)
$cols[$row->Field]=$row->Field;
}
$db_columns_ar_cache[$table]=$cols;
//debugexit($q1,$q2,$row,$coldata,$cols);
return $cols;
}
Notes:
As long as your tables first row does not contain megabyte range of data, it should work fine.
The function names db_rows and db_row_ar should be replaced with your specific database setup.
IN WORDPRESS:
global $wpdb; $table_name=$wpdb->prefix.'posts';
foreach ( $wpdb->get_col( "DESC " . $table_name, 0 ) as $column_name ) {
var_dump( $column_name );
}
Try this one out I personally use it:
SHOW COLUMNS FROM $table where field REGEXP 'stock_id|drug_name'
This question is old, but I got here looking for a way to find a given query its field names in a dynamic way (not necessarily only the fields of a table). And since people keep pointing this as the answer for that given task in other related questions, I'm sharing the way I found it can be done, using Gavin Simpson's tips:
//Function to generate a HTML table from a SQL query
function myTable($obConn,$sql)
{
$rsResult = mysqli_query($obConn, $sql) or die(mysqli_error($obConn));
if(mysqli_num_rows($rsResult)>0)
{
//We start with header. >>>Here we retrieve the field names<<<
echo "<table width=\"100%\" border=\"0\" cellspacing=\"2\" cellpadding=\"0\"><tr align=\"center\" bgcolor=\"#CCCCCC\">";
$i = 0;
while ($i < mysqli_num_fields($rsResult)){
$field = mysqli_fetch_field_direct($rsResult, $i);
$fieldName=$field->name;
echo "<td><strong>$fieldName</strong></td>";
$i = $i + 1;
}
echo "</tr>";
//>>>Field names retrieved<<<
//We dump info
$bolWhite=true;
while ($row = mysqli_fetch_assoc($rsResult)) {
echo $bolWhite ? "<tr bgcolor=\"#CCCCCC\">" : "<tr bgcolor=\"#FFF\">";
$bolWhite=!$bolWhite;
foreach($row as $data) {
echo "<td>$data</td>";
}
echo "</tr>";
}
echo "</table>";
}
}
This can be easily modded to insert the field names in an array.
Using a simple: $sql="SELECT * FROM myTable LIMIT 1" can give you the fields of any table, without needing to use SHOW COLUMNS or any extra php module, if needed (removing the data dump part).
Hopefully this helps someone else.
if you use php, use this gist.
it can get select fields full info with no result，and all custom fields such as:
SELECT a.name aname, b.name bname, b.*
FROM table1 a LEFT JOIN table2 b
ON a.id = b.pid;
if above sql return no data,will also get the field names aname, bname, b's other field name
just two line:
$query_info = mysqli_query($link, $data_source);
$fetch_fields_result = $query_info->fetch_fields();
This query fetches a list of all columns in a database without having to specify a table name. It returns a list of only column names:
SELECT COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_schema = 'db_name'
However, when I ran this query in phpmyadmin, it displayed a series of errors. Nonetheless, it worked. So use it with caution.
if you only need the field names and types (perhaps for easy copy-pasting into Excel):
SELECT COLUMN_NAME, DATA_TYPE
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA='databasenamegoeshere'
AND DATA_TYPE='decimal' and TABLE_NAME = 'tablenamegoeshere'
remove
DATA_TYPE='decimal'
if you want all data types
i no expert, but this works for me..
$sql = "desc MyTable";
$result = #mysql_query($sql);
while($row = #mysql_fetch_array($result)){
echo $row[0]."<br>"; // returns the first column of array. in this case Field
// the below code will return a full array-> Field,Type,Null,Key,Default,Extra
// for ($c=0;$c<sizeof($row);$c++){echo #$row[$c]."<br>";}
}
I have tried this query in SQL Server and this worked for me :
SELECT name FROM sys.columns WHERE OBJECT_ID = OBJECT_ID('table_name')
The call of DESCRIBE is working fine to get all columns of a table but if you need to filter on it, you need to use the SHOW COLUMNS FROM instead.
Example of PHP function to get all info of a table :
// get table columns (or return false if table not found)
function get_table_columns($db, $table) {
global $pdo;
if($cols = $pdo->query("DESCRIBE `$db`.`$table`")) {
if($cols = $cols->fetchAll(PDO::FETCH_ASSOC)) {
return $cols;
}
}
return false;
}
In my case, I had to find the primary key of a table. So, I used :
SHOW COLUMNS FROM `table` WHERE `Key`='PRI';
Here is my PHP function :
// get table Primary Key
function get_table_pk($db, $table) {
global $pdo;
$q = "SHOW COLUMNS FROM `$db`.`$table` WHERE `Key` = 'PRI'";
if($cols = $pdo->query($q)) {
if($cols = $cols->fetchAll(PDO::FETCH_ASSOC)) {
return $cols[0];
}
}
return false;
}