# sqlweld
sqlweld is a CLI tool designed to help manage large libraries of SQL statements that need to reuse the same SQL clauses.
- Permissions checks often look very similar between queries, and updating these clauses is both tedious and a potential
source of security bugs.
- Some queries need a number of slight variations, and while they can be formatted at runtime, this loses the benefits
that come from your queries being statically defined, especially with tools that do compile-time checking like
[sqlx](https://github.com/launchbadge/sqlx).
sqlweld is designed to help solve these problems. Query files are Liquid templates ending in the
`.sql.liquid` extension, and partials end with `.partial.sql.liquid`. The tool will render a `.sql` file for each
non-partial template it finds.
sqlweld is also a Rust library and can used from a `build.rs` file. By setting the `print_rerun_if_changed` option,
it will automatically print the appropriate statements to rerun if the queries change.
# Installation
Check the [releases page](https://github.com/dimfeld/sqlweld/releases) for Homebrew, npm, curl, and other options. Of course, `cargo install sqlweld` also works if you already have Rust installed.
# Watch Mode
Watch mode is not directly supported yet. Until it is, a tool such as [watchexec](https://watchexec.github.io/) can
accomplish the same functionality.
```shell
watchexec --exts liquid -- sqlweld
```
# Example
This example shows a simple use of the tool, with two queries that share a permissions check partial.
## Input
### get_some_objects.sql.liquid
```liquid
SELECT * FROM some_objects
WHERE id=$[obj_id] AND team = $[team_id]
AND {% render 'perm_check', table: "'some_objects'" %}
```
### update_some_objects.sql.liquid
```liquid
UPDATE some_objects
SET value = 'a'
WHERE id=$[obj_id] AND team = $[team_id]
AND {% render 'perm_check', action: "'write'", table: "'some_objects'" %}
```
### perm_check.partial.sql.liquid
```liquid
{%- unless user %}{% assign user = "$[user_id]" %}{% endunless -%}
{%- unless team %}{% assign team = "$[team_id]" %}{% endunless -%}
{%- unless action %}{% assign action = "'read'" %}{% endunless -%}
EXISTS (
SELECT 1
FROM permissions
WHERE user_id = {{ user }}
AND team_id = {{ team }}
AND action = {{ action }}
AND object_type = {{table}}
)
```
## Output
### get_some_objects.sql
```sql
SELECT * FROM some_objects
WHERE id=$[obj_id] AND team = $[team_id]
AND EXISTS (
SELECT 1
FROM permissions
WHERE user_id = $[user_id]
AND team_id = $[team_id]
AND action = 'read'
AND object_type = 'some_objects'
)
```
### update_some_objects.sql
```sql
UPDATE some_objects
SET value = 'a'
WHERE id=$[obj_id] AND team = $[team_id]
AND EXISTS (
SELECT 1
FROM permissions
WHERE user_id = $[user_id]
AND team_id = $[team_id]
AND action = 'write'
AND object_type = 'some_objects'
)
```