MySql: Can I Create array using sql - mysql

Question

I am Using Mysql DB. my question is : can i create array using sql?
if Yes then how and how to populate this array with output of following query -- "Select column_name1 From tableName".
Help me, Thanks in Advance

Answer 1

As I mentioned in my comment, MySQL does not support arrays by itself. That kind of structures are supported by other programming languages (like PHP, Java, Python, etcetera) and you can write a program capable of connecting to a MySQL database, read data from it and populate arrays (I think PostgreSQL supports an array data type, but I'm not sure).
What you can do is use cursors in a stored procedure to retreive data from a query and store it into variables.
Example:
delimiter $$
create procedure my_procedure()
begin
declare value varchar(100);
declare done int default false;
declare cur cursor for
select column_name1 from your_table;
declare continue handler for not found set done = true;
open cur; -- This line will open the row set and place the cursor
-- on the first row.
loop_data: loop
fetch cur into value; -- This line will fetch the current row
-- into the variable and move the cursor
-- to the next row.
if done then -- If there are no more rows in the
leave loop_data; -- row set, the loop is terminated here
end if; -- and the execution moves to the next
-- instruction after "end loop;"
-- do whatever you need to do with the retrieved value
end loop;
close cur;
end $$
delimiter ;
If you want to use an array in a high level programming language, you can do it using the appropriate methods. Here's an example using Java (read The Java tutorials: JDBC Database access for more info):
public class SomeClass {
/*
Retrieve data from a database and return an array with it.
Parameters:
- conn: Connection to the database.
*/
public String[] getValues(Connection conn) {
String[] ans = new String[10];
int i;
try(
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(
"select column_name1 from your_table limit 10"
);
) {
rs.beforeFirst();
i = 0;
while(rs.next()) {
ans[i] = rs.getString("column_name1");
i++;
}
} catch(SQLException e) {
// Code to handle the SQL exception
}
return ans;
}
}
References:
MySQL reference manual: Cursors

Answer 2

You can use an variable to simply select your row values into a string. Not precisely an array, but it allows you to store all your values into a single variable:
-- load test data
create table tableName (column_name1 varchar(5));
insert into tableName values
('abcde');
insert into tableName values
('fghij');
insert into tableName values
('klmno');
insert into tableName values
('pqrst');
insert into tableName values
('uvwzy');
insert into tableName values
('z');
-- build "array"
set #array := '';
select #array := concat(#array,column_name1) as array
from tableName;
select #array;