What is the difference between implode and join

An inner join of A and B gives the result of A intersect B, i. An outer join of A and B gives the results of A union B, i. An inner join using either of the equivalent queries gives the intersection of the two tables, i. A full outer join will give you the union of A and B, i. If something in A doesn't have a corresponding datum in B, then the B portion is null, and vice versa. This allows them to reference columns provided by preceding FROM items.

A LATERAL join is more like a correlated subquery, not a plain subquery, in that expressions to the right of a LATERAL join are evaluated once for each row left of it - just like a correlated subquery - while a plain subquery table expression is evaluated once only. The query planner has ways to optimize performance for either, though. Related answer with code examples for both side by side, solving the same problem:.

ON true :. A correlated subquery can only return a single value, not multiple columns and not multiple rows - with the exception of bare function calls which multiply result rows if they return multiple rows. The implode function in PHP is easily remembered as "array to string" , which simply means that it takes an array and returns a string. It rejoins any array elements and returns the resulting string, which may be put in a variable.

The explode function is used to " Split a string by a specified string into pieces i. The explode function in PHP allows us to break a string into smaller text with each break occurring at the same symbol.

This symbol is known as the delimiter. Using the explode command we will create an array from a string. The explode function breaks a string into an array, but the implode function returns a string from the elements of an array. So in this article, you saw how to use the implode and explode functions in PHP. Using this article one can easily understand the implode and explode functions in PHP.

Returns a string containing a string representation of all the array elements in the same order, with the separator string between each element. Example 1 implode example. Submit a Pull Request Report a Bug.

Parameters separator Defaults to an empty string. Return Values Returns a string containing a string representation of all the array elements in the same order, with the separator string between each element.