# Using advanced syntax for SQL queries

### SQL Query Interpolation Syntax

This page provides an overview of SQL interpolation techniques, focusing on how to dynamically inject parameterized values into SQL queries. It explains the differences between the `<%= %>` and `{{ }}` syntaxes for injecting frontend and backend variables, and offers practical examples for various data types and scenarios

#### Variable Injection Sources

* Frontend variables (set in app configuration or by requesters/filters):
  * Use `<%= %>` syntax
* Backend variables (from instance config or user attributes):
  * Use `{{ }}` syntax

#### String or Integer Values from User/Instance Context

For string attributes:

```sql
WHERE INDUSTRY = '\'{{ string_attribute }}\''
```

For numeric attributes:

```sql
WHERE INDUSTRY = '{{ numeric_attribute }}'
```

#### Checkbox Requester (Array) of Strings

Use "IN" instead of "=" and join syntax:

```sql
WHERE CATEGORY IN ('<%= requestersManager.requester_check.join("','") %>')
```

#### List of String Values from User Attributes/Instance Context

```sql
WHERE beer_kind IN ('{{ "\',\'".join(user.attributes.beer_kind) }}')
```

#### Array or List of Integers

For checkbox filter:

```sql
WHERE CATEGORY IN ('<%= requestersManager.requester_check.join(",") %>')
```

For user attributes:

```sql
WHERE beer_kind IN ('{{ ",".join(user.attributes.beer_kind) }}')
```

#### String Template Filtering

Based on user/instance context:

```sql
WHERE beer_kind LIKE '%{{ user.attributes.beer_kind }}%'
```

Based on requester value:

```sql
WHERE beer_kind LIKE '%<%= requestersManager.beerkind %>%'
```

#### List of String Templates from Checkbox Values

```sql
WHERE beer_kind LIKE '%<%=requestersManager.beerkind.length > 1 ?requestersManager.beerkind.join("%' OR beer_kind LIKE '%"):requestersManager.beerkind[0] %>%'
```

#### List of String Templates from User/Instance Context

```sql
WHERE beer_kind LIKE '%{{ ("%\' OR beer_kind LIKE \'%").join(user.attributes.beer_kind) if user.attributes.beer_kind|length > 0 else user.attributes.beer_kind[0] }}%'
```

This structure organizes the information into clear sections with appropriate headers, code blocks for SQL snippets, and consistent formatting.