Models¶

Defining a model¶

from buraq import models


class Post(models.Model):
    title        = models.CharField(max_length=200)
    slug         = models.SlugField(unique=True)
    content      = models.TextField()
    is_published = models.BooleanField(default=False)
    views        = models.IntegerField(default=0)
    created_at   = models.DateTimeField(auto_now_add=True)
    updated_at   = models.DateTimeField(auto_now=True)

    class Meta:
        table_name = "posts"

Field types¶

Field	Python type	SQL type
`CharField(max_length=N)`	`str`	`VARCHAR(N)`
`TextField()`	`str`	`TEXT`
`IntegerField()`	`int`	`INTEGER`
`PositiveIntegerField()`	`int`	`INTEGER CHECK > 0`
`BigIntegerField()`	`int`	`BIGINT`
`FloatField()`	`float`	`FLOAT`
`DecimalField(max_digits, decimal_places)`	`Decimal`	`NUMERIC`
`BooleanField()`	`bool`	`BOOLEAN`
`DateField()`	`date`	`DATE`
`DateTimeField()`	`datetime`	`DATETIME`
`TimeField()`	`time`	`TIME`
`EmailField()`	`str`	`VARCHAR(254)`
`URLField()`	`str`	`VARCHAR(200)`
`SlugField()`	`str`	`VARCHAR(50)`
`UUIDField()`	`UUID`	`VARCHAR(36)`
`JSONField()`	`dict/list`	`JSON`
`ForeignKey(model)`	model instance	`INTEGER` (FK)

Field options¶

All fields accept these common options:

models.CharField(
    max_length  = 200,
    required    = True,    # NOT NULL in SQL
    nullable    = False,   # same as required=False
    default     = "",      # default value
    unique      = False,   # UNIQUE constraint
    db_index    = False,   # CREATE INDEX
    primary_key = False,   # PRIMARY KEY
)

DateTimeField auto options¶

# Set to current time when the record is CREATED (never updated)
created_at = models.DateTimeField(auto_now_add=True)

# Set to current time every time the record is SAVED
updated_at = models.DateTimeField(auto_now=True)

Note

auto_now=True and auto_now_add=True cannot both be set on the same field.

ForeignKey¶

class Comment(models.Model):
    post   = models.ForeignKey("Post", on_delete="CASCADE")
    author = models.ForeignKey("User", on_delete="SET NULL", nullable=True)

on_delete options: "CASCADE", "SET NULL", "RESTRICT", "SET DEFAULT", "NO ACTION"

Meta class¶

class Post(models.Model):
    title = models.CharField(max_length=200)

    class Meta:
        table_name = "blog_posts"   # custom table name (default: class name lowercased + "s")