SQL model

The shared model describes catalogues, SQL types and analysed queries. Emitters and schema sources exchange these values without importing internal pipeline packages. The generator copies a source catalogue before analysis, so a schema source can return the same value again without generation changing it.

The model is split between two areas of the sdk kit, and each name has one home. Its schema and type half (Catalogue, Schema, Table, Column, TableName, SQLType and SQLTypeCategory, with NewColumn and NewSQLType to build them) belongs to seagull.sh/seagull/sdk/dialect, where a schema source fills a catalogue and an emitter reads the catalogue and the SQL types of its queries. Its query and Go-type half (AnalysedQuery, QueryParameter, OutputColumn, SQLTemplate, GoType, GoTypeResolver, TypeSlots and GeneratedFile with their companions) belongs to seagull.sh/seagull/sdk/emit, where emitters read it. The root package names the types an embedder configures (CustomFunction, GoType, TypeOverride, TypeSlots and Slot). A value the model reaches but no facade names, such as a catalogue's views, functions and enums, is read through the field that holds it.

Seagull follows the element, key, field and member types nested in a SQL type to dialect.MaxTypeDepth (64) levels. The built-in emitters refuse a type that nests that deep or deeper, through emit_kit.CheckTypeDepth, rather than read it in part. The type arguments of a go_type override may nest at most 16 levels.

Catalogue design explains ownership and replay; the generator API describes integration. Test integrations after upgrading Seagull because this API is evolving.

Source: sdk/dialect/facade.go and sdk/emit/facade.go.

Exported package inventory

These declarations are the model's part of the current go doc -short output of each package. Most are aliases of the implementation under internal/, which a program never imports; run go doc on a name for its doc comment.

Schema and types in sdk/dialect

Package source · Go package reference

go doc -short folds the type categories into their first, TypeCategoryInteger.

const TypeCategoryInteger = sqlmodel.TypeCategoryInteger ...
const MaxTypeDepth = sqlmodel.MaxTypeDepth
type Catalogue = sqlmodel.Catalogue
type Column = sqlmodel.Column
    func NewColumn(name string, sqlType SQLType, nullable bool) Column
type MigrationOrigin = sqlmodel.MigrationOrigin
type SQLType = sqlmodel.SQLType
    func NewSQLType(category SQLTypeCategory, engineName string) SQLType
type SQLTypeCategory = sqlmodel.SQLTypeCategory
type Schema = sqlmodel.Schema
type Table = sqlmodel.Table
type TableName = sqlmodel.TableName

Queries and Go types in sdk/emit

Package source · Go package reference

go doc -short folds the query commands, the segment kinds and the parameter directives into their first names.

const QueryCommandOne = sqlmodel.QueryCommandOne ...
const SegmentText = sqlmodel.SegmentText ...
const ParameterDirectiveNone = sqlmodel.ParameterDirectiveNone ...
type AllowedColumn = sqlmodel.AllowedColumn
type AnalysedQuery = sqlmodel.AnalysedQuery
type GeneratedFile = sqlmodel.GeneratedFile
type GoType = sqlmodel.GoType
type GoTypeResolver = sqlmodel.GoTypeResolver
type OutputColumn = sqlmodel.OutputColumn
type ParameterDirectiveKind = sqlmodel.ParameterDirectiveKind
type QueryCommand = sqlmodel.QueryCommand
type QueryParameter = sqlmodel.QueryParameter
type SQLSegment = sqlmodel.SQLSegment
type SQLSegmentKind = sqlmodel.SQLSegmentKind
type SQLTemplate = sqlmodel.SQLTemplate
type TypeSlot = sqlmodel.TypeSlot
type TypeSlots = sqlmodel.TypeSlots

In the root package

Package source · Go package reference

type CustomFunction = sqlmodel.CustomFunctionConfig
type GoType = sqlmodel.GoType
type Slot = sqlmodel.TypeSlot
type TypeOverride = sqlmodel.TypeOverride
type TypeSlots = sqlmodel.TypeSlots