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Introduction

Variables and constants store values you can later use anywhere in your query.

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Basic Usage

Variables are placeholders that can be assigned and reassigned values throughout the SQL code.

To assign a value to a variable, use the equal sign = followed by the value.

{name = 'foo'}
{age = 30}
{sum = 2 + 4}

Example in use:

---- Defining the variable and SQL code ----

{sum = 2 + 4} 

SELECT *
FROM table
WHERE id = {sum}

It’s transformed into:


SELECT *
FROM database
WHERE id = 6

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Incrementing

Variables can be modified using operations such as addition.

{counter = 10} -- Define the variable

SELECT *
FROM table
WHERE id != null
AND (
    {#each [1, 2, 3] as products, i}
        id = {counter}                       -- Print the value of the variable
        {counter = counter + 10}             -- Increment the value of the variable
        {#if i+1 < products.length} OR {/if} -- Add an OR to every element except the last one
    {/each}
)

It is transformed into:


SELECT *
FROM table
WHERE id != null 
AND (
  id = 10 OR
  id = 20 OR
  id = 30
)

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Constants

Constants are similar to variables but, once defined, their value cannot be changed. Also the main syntax difference is constants are defined using the @const keyword.

{@const name = 'value'}

---- Defining the constant and SQL code ----

{@const birthday = '2000/02/28'} 

SELECT *
FROM table
{#if birthday = '2000/02/28'}
    {birthday = '2024/12/31'} 
{/if}

It is transformed into:


'!Error: Cannot reassign a constant'

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Scope

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Global

Variables defined outside of any logic blocks are considered global and can be modified and accessed throughout the entire code.

{var1 = 'latitude'}

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Local Variables

Variables defined within logic blocks are local to that block. They cannot be accessed outside the block in which they are defined.

{#if condition}
    {var2 = 'localValue'} -- Accessible only within this block
{/if}
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