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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'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;
}
how to display count() sql function using php
$results = "SELECT count(votesnumber) FROM `votes` WHERE `candidate_id` = '$candidate_id'";
$queryresults = mysqli_query($connect, $results);
if($queryresults) {
$rowresults = mysqli_fetch_assoc($queryresults);
echo $rowresults['votesnumber'];
} else {
echo "error";
}
i want to display the results of sql count() function using php. am counting specific columns WHERE ID = "some value" in phpmyadmin its working but with php its giving me headache . any ideas on how to solve this?
Try this:
$results = "SELECT count(votesnumber) AS VoteNum FROM `votes` WHERE `candidate_id` = '$candidate_id'";
$queryresults = mysqli_query($connect, $results);
if($queryresults) {
$rowresults = mysqli_fetch_assoc($queryresults);
echo $rowresults['VoteNum'];
} else {
echo "error";
}
First, if you want to refer to the column name by a reference, then you need to give it a better name using an alias:
SELECT COUNT(votesnumber) as votesnumber
ROM `votes`
WHERE `candidate_id` = '$candidate_id';
Second, you should not be munging query strings with parameter values. Instead of '$candidate_id', learn to use parameters. This prevents unexpected syntax errors and SQL injection accounts.
Third, if votesnumber is actually a number of votes, then you probably want SUM() rather than COUNT().
You need to add "AS" instruction to your SQL if you want to get this data as a specific index from array (like $rowresults['votes']):
$results = "SELECT count(votesnumber) AS votes FROM `votes` WHERE `candidate_id` = '$candidate_id'";
Remember that you can always print_r() (for arrays) or var_dump() your variable to check if it contains data you want to have.
How would you write a prepared MySQL statement in PHP that takes a differing number of arguments each time? An example such query is:
SELECT `age`, `name` FROM `people` WHERE id IN (12, 45, 65, 33)
The IN clause will have a different number of ids each time it is run.
I have two possible solutions in my mind but want to see if there is a better way.
Possible Solution 1 Make the statement accept 100 variables and fill the rest with dummy values guaranteed not to be in the table; make multiple calls for more than 100 values.
Possible Solution 2 Don't use a prepared statement; build and run the query checking stringently for possible injection attacks.
I can think of a couple solutions.
One solution might be to create a temporary table. Do an insert into the table for each parameter that you would have in the in clause. Then do a simple join against your temporary table.
Another method might be to do something like this.
$dbh=new PDO($dbConnect, $dbUser, $dbPass);
$parms=array(12, 45, 65, 33);
$parmcount=count($parms); // = 4
$inclause=implode(',',array_fill(0,$parmcount,'?')); // = ?,?,?,?
$sql='SELECT age, name FROM people WHERE id IN (%s)';
$preparesql=sprintf($sql,$inclause); // = example statement used in the question
$st=$dbh->prepare($preparesql);
$st->execute($parms);
I suspect, but have no proof, that the first solution might be better for larger lists, and the later would work for smaller lists.
To make #orrd happy here is a terse version.
$dbh=new PDO($dbConnect, $dbUser, $dbPass);
$parms=array(12, 45, 65, 33);
$st=$dbh->prepare(sprintf('SELECT age, name FROM people WHERE id IN (%s)',
implode(',',array_fill(0,count($parms),'?'))));
$st->execute($parms);
There is also the FIND_IN_SET function whose second parameter is a string of comma separated values:
SELECT age, name FROM people WHERE FIND_IN_SET(id, '12,45,65,33')
decent sql wrappers support binding to array values.
i.e.
$sql = "... WHERE id IN (?)";
$values = array(1, 2, 3, 4);
$result = $dbw -> prepare ($sql, $values) -> execute ();
Please take #2 off the table. Prepared statements are the only way you should consider protecting yourself against SQL injection.
What you can do, however, is generate a dynamic set of binding variables. i.e. don't make 100 if you need 7 (or 103).
I got my answer from: http://bugs.php.net/bug.php?id=43568.
This is my working mysqli solution to my problem. Now I can dynamically use as many parameters as I want. They will be the same number as I have in an array or as in this case I am passing the ids from the last query ( which found all the ids where email = 'johndoe#gmail.com') to the dynamic query to get all the info about each of these id no matter how many I end up needing.
<?php $NumofIds = 2; //this is the number of ids I got from the last query
$parameters=implode(',',array_fill(0,$NumofIds,'?'));
// = ?,? the same number of ?'s as ids we are looking for<br />
$paramtype=implode('',array_fill(0,$NumofIds,'i')); // = ii<br/>
//make the array to build the bind_param function<br/>
$idAr[] = $paramtype; //'ii' or how ever many ?'s we have<br/>
while($statement->fetch()){ //this is my last query i am getting the id out of<br/>
$idAr[] = $id;
}
//now this array looks like this array:<br/>
//$idAr = array('ii', 128, 237);
$query = "SELECT id,studentid,book_title,date FROM contracts WHERE studentid IN ($parameters)";
$statement = $db->prepare($query);
//build the bind_param function
call_user_func_array (array($statement, "bind_param"), $idAr);
//here is what we used to do before making it dynamic
//statement->bind_param($paramtype,$v1,$v2);
$statement->execute();
?>
If you're only using integer values in your IN clause, there's nothing that argues against constructing your query dynamically without the use of SQL parameters.
function convertToInt(&$value, $key)
{
$value = intval($value);
}
$ids = array('12', '45', '65', '33');
array_walk($ids, 'convertToInt');
$sql = 'SELECT age, name FROM people WHERE id IN (' . implode(', ', $ids) . ')';
// $sql will contain SELECT age, name FROM people WHERE id IN (12, 45, 65, 33)
But without doubt the solution here is the more general approach to this problem.
I had a similiar problem today and I found this topic. Looking at the answers and searching around the google I found a pretty solution.
Although, my problem is a little bit more complicated. Because I have fixed binding values and dynamic too.
This is the mysqli solution.
$params = array()
$all_ids = $this->get_all_ids();
for($i = 0; $i <= sizeof($all_ids) - 1; $i++){
array_push($params, $all_ids[$i]['id']);
}
$clause = implode(',', array_fill(0, count($params), '?')); // output ?, ?, ?
$total_i = implode('', array_fill(0, count($params), 'i')); // output iiii
$types = "ss" . $total_i; // will reproduce : ssiiii ..etc
// %% it's necessary because of sprintf function
$query = $db->prepare(sprintf("SELECT *
FROM clients
WHERE name LIKE CONCAT('%%', ?, '%%')
AND IFNULL(description, '') LIKE CONCAT('%%', ?, '%%')
AND id IN (%s)", $clause));
$thearray = array($name, $description);
$merge = array_merge($thearray, $params); // output: "John", "Cool guy!", 1, 2, 3, 4
// We need to pass variables instead of values by reference
// So we need a function to that
call_user_func_array('mysqli_stmt_bind_param', array_merge (array($query, $types), $this->makeValuesReferenced($merge)));
And the function makeValuesreferenced:
public function makeValuesReferenced($arr){
$refs = array();
foreach($arr as $key => $value)
$refs[$key] = &$arr[$key];
return $refs;
}
Links for getting this 'know-how': https://bugs.php.net/bug.php?id=49946, PHP append one array to another (not array_push or +), [PHP]: Error -> Too few arguments in sprintf();, http://no2.php.net/manual/en/mysqli-stmt.bind-param.php#89171, Pass by reference problem with PHP 5.3.1
Got a question for you all...
What would be the best way to search my table by array, that has an array in the table.
EG:
$var = (1,4,7,9,14)
$Query = "SELECT * FROM business_listings WHERE category IN ($var)";
'category' would have 4,27,89,101
How can I get this to match if one of the numbers in the $var matches one of the numbers in the table.
If your database column is a list of comma separated values, and you're searching for one value in that list, then you're in a different situation.
If your category column contains the text value 410,406,149,152, like you commented below, and you're searching for fields whose category contains 152, then you'll need to use MySQL's FIND_IN_SET() function.
If you have to check multiple values, then you need to use more than one FIND_IN_SET. If you read the documentation, you'll see that the first argument for FIND_IN_SET must be a single string, not a string list (it can't contain a comma). Use the following instead:
$var = "401,320,152";
$items = explode(",", $var);
foreach ($items as &$i) {
$i = "FIND_IN_SET('" . $i . "', `category`)";
}
$search = implode(" OR ", $items);
unset($i);
$query = "SELECT * FROM business_listings WHERE " . $items;
This will output:
SELECT * FROM business_listings WHERE
FIND_IN_SET('401', `category`) OR
FIND_IN_SET('320', `category`) OR
FIND_IN_SET('152', `category`)
The above script will work even if $var contains only one value.
Finally, as tadman mentioned, since we're getting into queries that can be tricky to build with prepared statements, you need to make sure you're escaping and sanitizing your input properly. For an example, if $var is being retrieved from the user somehow, then before you modify it in any way, you need to escape it with mysqli_real_escape_string():
$var = $mysqli->real_escape_string($var);
Assuming that $mysqli is your open MySQLi connection.
Hope this helps!