Make it possible to add fully custom columns to table definition

This adds a few different fields to the column SQL builder that were
once either calculated or hard-coded:
 * Import - so you can import the column from anywhere
 * Type - fully, rather than partially, modifiable to allow any naming
   convention
 * TypeFactory - fully, rather than partially defined

I also alphabetized some things because the OCD compels me.

generator/metadata/table_meta_data.go

@@ -2,9 +2,10 @@ package metadata
 
 // Table metadata struct
 type Table struct {
-	Name    string `sql:"primary_key"`
 	Comment string
 	Columns []Column
+	Imports []string
+	Name    string `sql:"primary_key"`
 }
 
 // MutableColumns returns list of mutable columns for table

generator/template/file_templates.go

@@ -14,7 +14,9 @@ var tableSQLBuilderTemplate = `
 package {{package}}
 
 import (
-	"github.com/go-jet/jet/v2/{{dialect.PackageName}}"
+{{- range $i, $import := imports .Columns}}
+	"{{$import}}"
+{{- end}}
 )
 
 var {{tableTemplate.InstanceName}} = new{{tableTemplate.TypeName}}("{{schemaName}}", "{{.Name}}", "{{tableTemplate.DefaultAlias}}")
@@ -27,7 +29,7 @@ type {{structImplName}} struct {
 {{- range $i, $c := .Columns}}
 {{- $field := columnField $c}}
 {{- if not $field.Skip}}
-	{{$field.Name}} {{dialect.PackageName}}.Column{{$field.Type}} {{golangComment .Comment}}
+	{{$field.Name}} {{$field.PackageName}}.{{$field.Type}} {{golangComment .Comment}}
 {{- end}}
 {{- end}}
 
@@ -74,7 +76,7 @@ func new{{tableTemplate.TypeName}}Impl(schemaName, tableName, alias string) {{st
 {{- range $i, $c := .Columns}}
 {{- $field := columnField $c}}
 {{- if not $field.Skip }}
-		{{$field.Name}}Column = {{dialect.PackageName}}.{{$field.Type}}Column("{{$c.Name}}")
+		{{$field.Name}}Column = {{$field.PackageName}}.{{$field.TypeFactory}}("{{$c.Name}}")
 {{- end}}
 {{- end}}
 		allColumns     = {{dialect.PackageName}}.ColumnList{ {{columnList .Columns}} }

generator/template/process.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"sort"
 	"strings"
 	"text/template"
 
@@ -15,6 +16,7 @@ import (
 	"github.com/go-jet/jet/v2/internal/jet"
 )
 
+type Dialect = jet.Dialect
 // ProcessSchema will process schema metadata and constructs go files using generator Template
 func ProcessSchema(dirPath string, schemaMetaData metadata.Schema, generatorTemplate Template) error {
 	if schemaMetaData.IsEmpty() {
@@ -194,34 +196,13 @@ func processTableSQLBuilder(fileTypes, dirPath string,
 			autoGenWarningTemplate+tableSQLBuilderTemplate,
 			tableMetaData,
 			template.FuncMap{
-				"package": func() string {
-					return tableSQLBuilder.PackageName()
-				},
-				"dialect": func() jet.Dialect {
-					return dialect
-				},
-				"schemaName": func() string {
-					return schemaMetaData.Name
-				},
-				"tableTemplate": func() TableSQLBuilder {
-					return tableSQLBuilder
-				},
-				"structImplName": func() string { // postgres only
-					structName := tableSQLBuilder.TypeName
-					return string(strings.ToLower(structName)[0]) + structName[1:]
-				},
 				"columnField": func(columnMetaData metadata.Column) TableSQLBuilderColumn {
-					return tableSQLBuilder.Column(columnMetaData)
+					return tableSQLBuilder.Column(dialect, columnMetaData)
 				},
-				"toUpper": strings.ToUpper,
-				"insertedRowAlias": func() string {
-					return insertedRowAlias(dialect)
-				},
-				"golangComment": formatGolangComment,
 				"columnList": func(columns []metadata.Column) string {
 					names := []string{}
 					for _, col := range columns {
-						bc := tableSQLBuilder.Column(col)
+						bc := tableSQLBuilder.Column(dialect, col)
 						if bc.Skip {
 							continue
 						}
@@ -229,6 +210,40 @@ func processTableSQLBuilder(fileTypes, dirPath string,
 					}
 					return strings.Join(names, ", ")
 				},
+				"dialect": func() jet.Dialect {
+					return dialect
+				},
+				"golangComment": formatGolangComment,
+				"imports": func(columns []metadata.Column) []string {
+					imports := make(map[string]struct{}, 0)
+					for _, columnMetaData := range columns {
+						c := tableSQLBuilder.Column(dialect, columnMetaData)
+						imports[c.Import] = struct{}{}
+					}
+					results := make([]string, 0)
+					for k, _ := range imports {
+						results = append(results, k)
+					}
+					sort.Strings(results)
+					return results
+				},
+				"insertedRowAlias": func() string {
+					return insertedRowAlias(dialect)
+				},
+				"package": func() string {
+					return tableSQLBuilder.PackageName()
+				},
+				"schemaName": func() string {
+					return schemaMetaData.Name
+				},
+				"structImplName": func() string { // postgres only
+					structName := tableSQLBuilder.TypeName
+					return string(strings.ToLower(structName)[0]) + structName[1:]
+				},
+				"tableTemplate": func() TableSQLBuilder {
+					return tableSQLBuilder
+				},
+				"toUpper": strings.ToUpper,
 			})
 		if err != nil {
 			return fmt.Errorf("failed to generate table sql builder type %s: %w", tableSQLBuilder.TypeName, err)

generator/template/sql_builder_template.go

@@ -8,6 +8,7 @@ import (
 	"unicode"
 
 	"github.com/go-jet/jet/v2/generator/metadata"
+	"github.com/go-jet/jet/v2/internal/jet"
 	"github.com/go-jet/jet/v2/internal/utils/dbidentifier"
 )
 
@@ -62,13 +63,14 @@ func (sb SQLBuilder) ShouldSkip(skip bool) SQLBuilder {
 
 // TableSQLBuilder is template for generating table SQLBuilder files
 type TableSQLBuilder struct {
-	Skip         bool
-	Path         string
-	FileName     string
-	InstanceName string
-	TypeName     string
+	Column       func(dialect jet.Dialect, columnMetaData metadata.Column) TableSQLBuilderColumn
 	DefaultAlias string
-	Column       func(columnMetaData metadata.Column) TableSQLBuilderColumn
+	Imports []string
+	InstanceName string
+	FileName     string
+	Path         string
+	Skip         bool
+	TypeName     string
 }
 
 // ViewSQLBuilder is template for generating view SQLBuilder files
@@ -79,12 +81,13 @@ func DefaultTableSQLBuilder(tableMetaData metadata.Table) TableSQLBuilder {
 	tableNameGoIdentifier := dbidentifier.ToGoIdentifier(tableMetaData.Name)
 
 	return TableSQLBuilder{
-		Path:         "/table",
-		FileName:     dbidentifier.ToGoFileName(tableMetaData.Name),
-		InstanceName: tableNameGoIdentifier,
-		TypeName:     tableNameGoIdentifier + "Table",
-		DefaultAlias: "",
 		Column:       DefaultTableSQLBuilderColumn,
+		DefaultAlias: "",
+		FileName:     dbidentifier.ToGoFileName(tableMetaData.Name),
+		Imports:  []string{},
+		InstanceName: tableNameGoIdentifier,
+		Path:         "/table",
+		TypeName:     tableNameGoIdentifier + "Table",
 	}
 }
 
@@ -131,16 +134,19 @@ func (tb TableSQLBuilder) UseDefaultAlias(defaultAlias string) TableSQLBuilder {
 }
 
 // UseColumn returns new TableSQLBuilder with new column template function set
-func (tb TableSQLBuilder) UseColumn(columnsFunc func(column metadata.Column) TableSQLBuilderColumn) TableSQLBuilder {
+func (tb TableSQLBuilder) UseColumn(columnsFunc func(dialect jet.Dialect, column metadata.Column) TableSQLBuilderColumn) TableSQLBuilder {
 	tb.Column = columnsFunc
 	return tb
 }
 
 // TableSQLBuilderColumn is template for table sql builder column
 type TableSQLBuilderColumn struct {
-	Skip bool
+	Import string
 	Name string
+	PackageName string
+	Skip bool
 	Type string
+	TypeFactory string
 }
 
 var reservedKeywords = []string{"TableName", "Table", "SchemaName", "Alias", "AllColumns", "MutableColumns", "DefaultColumns"}
@@ -153,10 +159,14 @@ func renameIfReserved(name string) string {
 }
 
 // DefaultTableSQLBuilderColumn returns default implementation of TableSQLBuilderColumn
-func DefaultTableSQLBuilderColumn(columnMetaData metadata.Column) TableSQLBuilderColumn {
+func DefaultTableSQLBuilderColumn(dialect jet.Dialect, columnMetaData metadata.Column) TableSQLBuilderColumn {
+	package_name := dialect.PackageName()
 	return TableSQLBuilderColumn{
+		Import: "github.com/go-jet/jet/v2/" + package_name,
 		Name: renameIfReserved(dbidentifier.ToGoIdentifier(columnMetaData.Name)),
-		Type: getSqlBuilderColumnType(columnMetaData),
+		PackageName: package_name,
+		Type: "Column" + getSqlBuilderColumnType(columnMetaData),
+		TypeFactory: getSqlBuilderColumnType(columnMetaData)+"Column",
 	}
 }