I am wanting to count all occurrences of the # symbol in a field and originally i thought LIKE '%#%' would be the way to go, but if the character appears in the field more than once it only counts it as one.
What other method are there that i could use that would count every occurrence?
Thanks.
EDIT
For anyone needing it, this is what i ended up using that works.
$count = 0;
$sql = mysql_query("SELECT LENGTH(field_name) - LENGTH(REPLACE(field_name,'#','')) AS 'occurs' FROM table_name WHERE field_name LIKE '%#%'");
while ($data = mysql_fetch_assoc($sql)) {
$count += $data['occurs'];
}
echo $count;
select length('aa:bb:cc:dd')-length(replace('aa:bb:cc:dd',':',''));
source: http://lists.mysql.com/mysql/215049
You could make this even simpler by using the ``substr_count function in php. see below.
$message = $row['themessage'];
echo substr_count($message, '#');
what this will return is the number of times # has occurred in your "themessage" field in your database.
i have question i don't know better approach to do it in mysql. I have a table in mysql with list of regex's each regex represent a company order number
i want to be able to compare a number to that list to get which company this number belongs to. the lazy way is to list all the regex in php and then using loop to get the company , but i want to do this using the power of mysql .
Like #Mech mention this might be vague.
i will try to explain it more :
I have two tables table with actual regex pattern in plain text in a column like "^[8]{1}[0-9]{10}$"
and this pattern belong to a company , there is more than 500 regex patterns .
Thank you.
Here you go #BM2ilabs. A function as requested :)
carrierID(88888141234);
function carrierID($ordernum) {
// create a connection to your db here
// fetch data needed for loop
$sql = "SELECT regex, carrier_id FROM `company_tbl_from_image`";
// fetch results
$results = $conn->query($sql);
// loop through $results
foreach ($results as $result) {
// individually check against each regex in the table
$regex = $result[regex];
// find first instance of $regex, where the $ordernum is unique, there should only be one match
if (preg_match('/'.$regex.'/', $ordernum)) {
$carrier_id = $result[carrier_id];
break; // remove break to show other matches
}
}
// check if $carrier_id is empty
if ($carrier_id <> "") {
echo $carrier_id;
} else {
echo "No carrier ID found.";
}
}
MySQL only option. Just search this:
SELECT carrier_id FROM `company_tbl_from_image` WHERE 'order number' REGEXP regex
for($count = 0; $count < count($_POST["item_sub_category"]); $count++)
{
$data = array(
':item_sub_category_id'
=> SELECT r_name FROM Repair where r_id = $_POST["item_sub_category"][$count]
);
$query = "INSERT INTO Repairlog (description,visitID) VALUES (:item_sub_category_id,'1')";
$statement = $connect->prepare($query);
$statement->execute($data);
}
As far as concerns, your code won't work. The SQL query that you are passing as a parameter will simply be interpreted as a string.
You could avoid the need for a loop by taking advantage of the INSERT INTO ... SELECT ... syntax. The idea is to generate an IN clause that contains all values that are in the array, and then run a single query to insert all records at once.
Consider:
$in = str_repeat('?,', count($_POST["item_sub_category"]) - 1) . '?';
$query = "INSERT INTO Repairlog (description,visitID) SELECT r_name, 1 FROM Repair WHERE r_id IN ($in)";
$statement = $connect->prepare($query);
$statement->execute($_POST["item_sub_category"]);
Note: it is likely that visitID is an integer and not a string; if so, then it is better not to surround the value with single quotes (I removed them in the above code).
TLDR; No.
Your question can be re-framed as: Can I write SQL code in php. The answer is NO. You can write the SQL code within a String type variable (or parameter) in php.
This is a general rule for any programming language, you cannot have multiple languages within the same file, as the language parser will not be able understand which syntax is that.
In order to embed a different language in another language, you need some kind of separator that will define when the new language or special type will start and when it will end.
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;
}
I'm trying to figure out an efficient way to select a small list of random ids from a table.
Using the IN operator seems like the right choice, but I don't understand how use the results the way I want. After the query is made how do I use the results to assign to specific variables? or is there a way to assign the values as part of the query?
$red_car1=1001;
$blue_car2=200;
$green_car3=56;
$query_cars= sprintf("SELECT * FROM cars WHERE id IN (%s, %s, %s)", $red_car1, $blue_car4, $green_car3);
$Cars1 = mysql_query($query_cars, $db) or die(mysql_error());
$red_car1_vin = $row_Cars1['vin'];
$blue_car1_vin = $row_Cars1['vin'];
$green_car1_vin = $row_Cars1['vin'];
Get yourself familiar with prepared statements. Prepare your statement once and execute it n times with n variables. It's quite efficient.
Or itterate over your results:
$tmp = array();
while($row_Cars1 = mysql_fetch_array($Cars1))
{
$tmp[$row_Cars1['id']] = $row_Cars1;
}
Now you have an associative array with your results and you can use it like:
$red_car1_vin = $tmp[$red_car1];
If your server side language is PHP, then your code should be like -
$con=mysqli_connect("your host","user","password","your db");
$red_car1=1001;
$blue_car2=200;
$green_car3=56;
$query_cars= "SELECT * FROM cars WHERE id
IN (".$red_car1.",".$blue_car2.",".$green_car3.")";
$Cars1 = mysqli_query($con,$query_cars) or die(mysql_error());
while($row = mysqli_fetch_array($Cars1))
{
echo $row['<<Your Desired field name1>>'] . " " . $row['<<Your Desired field name2>>'];// and so on
echo "<br />";
}
mysqli_close($con);
Also you can have more helpful information here -http://www.w3schools.com/php/php_mysql_select.asp
Thanks