Fields

Field expressions provide type-safe access to model fields. Use them in queries to ensure compile-time type checking.

Complete reference for all field types and options.

Field Types

Numeric Fields

Int64

64-bit integer:

schema.Int64("id").Primary().AutoIncrement().Build()
schema.Int64("age").Build()

Int32

32-bit integer:

schema.Int32("count").Build()

Float64

64-bit floating point:

schema.Float64("price").Build()

Decimal

Decimal with precision:

schema.Decimal("amount").
    MaxDigits(10).
    DecimalPlaces(2).
    Build()

String Fields

String

Variable-length string:

schema.String("username").
    MaxLength(150).
    Required().
    Build()

Text

Unlimited text:

schema.Text("content").Build()

Email

Email field with validation:

schema.Email("email").
    Unique().
    Required().
    Build()

URL

URL field with validation:

schema.URL("website").Build()

Slug

URL-friendly string:

schema.Slug("slug").
    MaxLength(200).
    Unique().
    Build()

Boolean Fields

Bool

Boolean field:

schema.Bool("is_active").
    Default(true).
    Build()

Date and Time Fields

Time

Timestamp:

schema.Time("created_at").
    AutoNowAdd().
    Build()

Date

Date only:

schema.Date("birth_date").Build()

DateTime

Date and time:

schema.DateTime("last_login").Build()

Special Fields

UUID

UUID field:

schema.UUID("id").Primary().Build()

JSON

JSON field:

schema.JSON("metadata").Build()

Bytes

Binary data:

schema.Bytes("avatar").Build()

Field Options

All field types support these options:

Required

Make field required (NOT NULL):

schema.String("username").Required().Build()

Unique

Add unique constraint:

schema.String("email").Unique().Build()

Primary

Set as primary key:

schema.Int64("id").Primary().Build()

Index

Create database index:

schema.String("username").Index().Build()

DBColumn

Custom column name:

schema.String("firstName").DBColumn("first_name").Build()

Default

Default value:

schema.Bool("is_active").Default(true).Build()
schema.String("status").Default("pending").Build()

MaxLength

Maximum length (strings):

schema.String("username").MaxLength(150).Build()

MinLength

Minimum length (strings):

schema.String("password").MinLength(8).Build()

MaxDigits

Maximum digits (decimal):

schema.Decimal("amount").
    MaxDigits(10).
    DecimalPlaces(2).
    Build()

DecimalPlaces

Decimal places (decimal):

schema.Decimal("price").
    MaxDigits(10).
    DecimalPlaces(2).
    Build()

Choices

Predefined choices:

schema.String("status").
    Choices("active", "pending", "deleted").
    Build()

Null

Allow NULL:

schema.String("middle_name").Null().Build()

Blank

Allow blank (strings):

schema.String("description").Blank().Build()

HelpText

Help text for admin:

schema.String("username").
    HelpText("Required. 150 characters or fewer.").
    Build()

VerboseName

Human-readable name:

schema.String("firstName").
    VerboseName("First Name").
    Build()

Editable

Make read-only in admin:

schema.Time("created_at").
    Editable(false).
    Build()

AutoNow

Set on save:

schema.Time("updated_at").AutoNow().Build()

AutoNowAdd

Set on create only:

schema.Time("created_at").AutoNowAdd().Build()

AutoIncrement

Auto-incrementing (primary keys):

schema.Int64("id").
    Primary().
    AutoIncrement().
    Build()

Field Type Reference Table

Field Type	Go Type	SQL Type	Builder
Int64	int64	BIGINT	schema.Int64()
Int32	int32	INTEGER	schema.Int32()
String	string	VARCHAR(n)	schema.String()
Text	string	TEXT	schema.Text()
Bool	bool	BOOLEAN	schema.Bool()
Float64	float64	DOUBLE PRECISION	schema.Float64()
Decimal	decimal.Decimal	NUMERIC	schema.Decimal()
Time	time.Time	TIMESTAMP	schema.Time()
Date	time.Time	DATE	schema.Date()
DateTime	time.Time	TIMESTAMP	schema.DateTime()
Email	string	VARCHAR(255)	schema.Email()
URL	string	VARCHAR(255)	schema.URL()
UUID	string	UUID	schema.UUID()
JSON	[]byte	JSONB	schema.JSON()
Bytes	[]byte	BYTEA	schema.Bytes()

See Also

• Schema Reference - Model definition
• Models Guide - Model usage guide