SQL Constraints helps to set validation for the record sets, which act as a reminder for the user for the workflow.

1. Model Constraints - SQL
Constraints Odoo 16

2. ● SQL Constraints which are defined through the model attribute
_sql_constraints.
● SQL Constraints also give the same purpose of python
constraints.
● SQL Constraints helps to set validation for the recordsets,which
act as a reminder for the user for the workflow.

3. Types Of SQL Constraints
1. Not Null
2. Check
3. Unique

4. How SQL Constraints Work
Example Model:
Class TestModel(model.Model):
_name=’test.model’
_description=’Test Model’
name=fields.Char()
channel_type=fields.Selection([(‘chat’,’Chat’),(‘channel’,’Channel’)])
probability=fields.Float()

5. Not Null
This constraint ensures that no field can be empty or null.
Eg : _sql_constraints=[(‘channel_type_not_null’,’CHECK(channel_type IS NOT NULL)’,The
Channel Type Cannot be Empty’)]
● This is a tuple that defines a single check constraint.
● The first member of the tuple “channel_type_not_null” is a string that defines the constraints
name.The name may be whatever you like as long as it is unique to the model.

6. Not Null
● The second member of the tuple,CHECK(channel_type IS NOT NULL), defines the
check constraint.In this case ,the constraint checks whether the channel_type field is
not null.If the channel_type field is null,the constraint will be violated and an error will be
raised.
● The third member of the tuple,’The Channel Type Cannot be Empty’,is a string that
provides an error message that will be displayed to the user if the constraint is violated.

7. Check
This Constraint allows users to define custom rules that must be met for a field.
Check Constraint is a rule that restricts the data that can be inserted or updated in a table,to
ensure data integrity and consistency.
Eg : _sql_constraints=[(‘check_probabilty’,’CHECK(probability>=0 and
probability<=0)’,The Probability should be Between 0% and 100%!’ )]

8. Check
● The first member of the tuple “check_probability” is a string that defines the constraints
name.The name may be whatever you like as long as it is unique to the model.
● The second member,checks the value of the “probability” field in the table between 0
and 100(inclusive) using the SQL “check” constraint.
● This is a tuple that defines a single check constraint.

9. Unique
This constraint ensures that each value in a field is unique.
Eg : _sql_constraints = [(‘uniq_name_’,UNIQUE(name)’, ‘Name Must Be
Unique’)]
● The First element is the constraint name
● The Second element defines unique constraint,In this case the
constraint ensures that each value in the name fields is unique across all
records in the table associated with the model.
● The Third element be the warning message.

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