Add check constraints safely in SQLAlchemy

postgresqlsqlalchemyalembicmigrations
When adding check constraints that could affect large tables, create the constraint with `NOT VALID` first to avoid blocking writes during the validation scan.
Bad:
```python
def upgrade():
    # Directly creating a check constraint blocks writes during table scan
    op.create_check_constraint(
        'ck_users_age_positive',

Install this rule for wispbit

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curl -fsSL https://wispbit.com/api/install?rule=sqlalchemy-split-check-constraint | bash

Manual install

1

Copy the rule

---
include: *.py
---
When adding check constraints that could affect large tables, create the constraint with `NOT VALID` first to avoid blocking writes during the validation scan.
Bad:
```python
def upgrade():
    # Directly creating a check constraint blocks writes during table scan
    op.create_check_constraint(
        'ck_users_age_positive',
        'users',
        'age >= 0'
    )
```
Good:
```python
# Migration 1: Create check constraint without validation
def upgrade():
    # Create the check constraint without validating existing data (non-blocking)
    op.create_check_constraint(
        'ck_users_age_positive',
        'users',
        'age >= 0',
        postgresql_not_valid=True
    )
```
```python
# Migration 2: Validate existing data
def upgrade():
    op.execute('ALTER TABLE users VALIDATE CONSTRAINT ck_users_age_positive')
```
2

Add the rule into your project

Save the copied content as: .wispbit/rules/sqlalchemy-split-check-constraint.md

Install this rule for Coderabbit

Copy the configuration below and add it to your repository as .coderabbit.yml in your project root.

reviews:
  path_instructions:
    - path: "*.py"
      instructions: |
                
        When adding check constraints that could affect large tables, create the constraint with `NOT VALID` first to avoid blocking writes during the validation scan.
        
        Bad:
        
        ```python
        def upgrade():
            # Directly creating a check constraint blocks writes during table scan
            op.create_check_constraint(
                'ck_users_age_positive',
                'users',
                'age >= 0'
            )
        ```
        
        Good:
        
        ```python
        # Migration 1: Create check constraint without validation
        
        def upgrade():
            # Create the check constraint without validating existing data (non-blocking)
            op.create_check_constraint(
                'ck_users_age_positive',
                'users',
                'age >= 0',
                postgresql_not_valid=True
            )
        ```
        
        ```python
        # Migration 2: Validate existing data
        
        def upgrade():
            op.execute('ALTER TABLE users VALIDATE CONSTRAINT ck_users_age_positive')
        ```

Install this rule for Greptile

Greptile rules can be added through the web interface. Please see this documentation for details on how to add custom rules and context.

When adding check constraints that could affect large tables, create the constraint with `NOT VALID` first to avoid blocking writes during the validation scan.
Bad:
```python
def upgrade():
    # Directly creating a check constraint blocks writes during table scan
    op.create_check_constraint(
        'ck_users_age_positive',
        'users',
        'age >= 0'
    )
```
Good:
```python
# Migration 1: Create check constraint without validation
def upgrade():
    # Create the check constraint without validating existing data (non-blocking)
    op.create_check_constraint(
        'ck_users_age_positive',
        'users',
        'age >= 0',
        postgresql_not_valid=True
    )
```
```python
# Migration 2: Validate existing data
def upgrade():
    op.execute('ALTER TABLE users VALIDATE CONSTRAINT ck_users_age_positive')
```

File Path Patterns:

*.py

Install this rule for GitHub Copilot

Copilot instructions can be added through the interface. See the documentation for details on how to create coding guidelines.

When adding check constraints that could affect large tables, create the constraint with `NOT VALID` first to avoid blocking writes during the validation scan.
Bad:
```python
def upgrade():
    # Directly creating a check constraint blocks writes during table scan
    op.create_check_constraint(
        'ck_users_age_positive',
        'users',
        'age >= 0'
    )
```
Good:
```python
# Migration 1: Create check constraint without validation
def upgrade():
    # Create the check constraint without validating existing data (non-blocking)
    op.create_check_constraint(
        'ck_users_age_positive',
        'users',
        'age >= 0',
        postgresql_not_valid=True
    )
```
```python
# Migration 2: Validate existing data
def upgrade():
    op.execute('ALTER TABLE users VALIDATE CONSTRAINT ck_users_age_positive')
```

File Path Patterns:

*.py

Install this rule for Graphite Diamond

Diamond custom rules can be added through the interface. See the documentation for details on how to create custom rules.

When adding check constraints that could affect large tables, create the constraint with `NOT VALID` first to avoid blocking writes during the validation scan.
Bad:
```python
def upgrade():
    # Directly creating a check constraint blocks writes during table scan
    op.create_check_constraint(
        'ck_users_age_positive',
        'users',
        'age >= 0'
    )
```
Good:
```python
# Migration 1: Create check constraint without validation
def upgrade():
    # Create the check constraint without validating existing data (non-blocking)
    op.create_check_constraint(
        'ck_users_age_positive',
        'users',
        'age >= 0',
        postgresql_not_valid=True
    )
```
```python
# Migration 2: Validate existing data
def upgrade():
    op.execute('ALTER TABLE users VALIDATE CONSTRAINT ck_users_age_positive')
```

File Path Patterns:

*.py