从多个 MySQL 表中选择数据

Question

Im searching for a function in MySQL in order to Select rows from multiple tables that have a similar name. For example: Proyect_1, Proyect_2, Proyect_3

All of the tables have the same column names, the only difference between the tables is the table name. It starts with the prefix 'proyect'. The issue is that the program doesn´t know how many 'proyect' tables there are, so i can´t make a list of them and select data like always

I need something like this:

SELECT mydata FROM TABLES LIKE 'Proyect_%';

Any ideas? Thanks!

Answer 1

if you want to search for all tables with name like Proyect then you can get from MySQL information schema.

SELECT * FROM information_schema.tables 

From here you can find table by table name

Answer 2

To get all tables with a common prefix

SHOW TABLES LIKE 'Proyect_%';

This will return rows of tables that matched the prefix. Example:

Proyect_1
Proyect_2
Proyect_3

In PHP you can create a UNION query that will pick up the tables returned by the above query,

$sql = "SHOW TABLES LIKE 'Proyect_%'";
$result = $conn->query($sql);

$dataQuery = array();
$query = "";
if ($result->num_rows > 0) {
  // output data of each row
  while($row = $result->fetch_array(MYSQLI_NUM)) {
     $dataQuery[] = "SELECT * FROM {$row[0]}";
  }
  $query = implode(' UNION ', $dataQuery);
}

echo $query;