Add self join support.

generator/metadata/column_info.go

@@ -23,7 +23,7 @@ func (c ColumnInfo) IsUnique() bool {
 }
 
 func (c ColumnInfo) ToGoVarName() string {
-	return snaker.SnakeToCamelLower(c.TableInfo.Name) + snaker.SnakeToCamel(c.Name) + "Column"
+	return snaker.SnakeToCamel(c.Name) + "Column"
 }
 
 func (c ColumnInfo) ToGoType() string {

generator/templates.go

@@ -2,7 +2,9 @@ package generator
 
 var SqlBuilderTableTemplate = `package table
 
-import "github.com/sub0Zero/go-sqlbuilder/sqlbuilder"
+import (
+	"github.com/sub0Zero/go-sqlbuilder/sqlbuilder"
+)
 
 type {{.ToGoStructName}} struct {
 	sqlbuilder.Table
@@ -15,22 +17,36 @@ type {{.ToGoStructName}} struct {
 	AllColumns sqlbuilder.ColumnList
 }
 
-var {{.ToGoVarName}} = &{{.ToGoStructName}}{
-	Table: *sqlbuilder.NewTable("{{.DatabaseInfo.SchemaName}}", "{{.Name}}", {{.ToGoColumnFieldList ", "}}),
-	
-	//Columns
+var {{.ToGoVarName}} = new{{.ToGoStructName}}()
+
+func new{{.ToGoStructName}}() *{{.ToGoStructName}} {
+	var (
+	{{- range .Columns}}
+		{{.ToGoVarName}} = sqlbuilder.IntColumn("{{.Name}}", {{if .IsNullable}}sqlbuilder.Nullable{{else}}sqlbuilder.NotNullable{{end}})
+	{{- end}}
+	)
+
+	return &{{.ToGoStructName}}{
+		Table: *sqlbuilder.NewTable("{{.DatabaseInfo.SchemaName}}", "{{.Name}}", {{.ToGoColumnFieldList ", "}}),
+
+		//Columns
 {{- range .Columns}}
-	{{.ToGoFieldName}}: {{.ToGoVarName}},
+		{{.ToGoFieldName}}: {{.ToGoVarName}},
 {{- end}}
 
-	AllColumns: sqlbuilder.ColumnList{ {{.ToGoColumnFieldList ", "}} },
+		AllColumns: sqlbuilder.ColumnList{ {{.ToGoColumnFieldList ", "}} },
+	}
+}
+
+
+func (a *{{.ToGoStructName}}) As(alias string) *{{.ToGoStructName}} {
+	aliasTable := new{{.ToGoStructName}}()
+
+	aliasTable.Table.SetAlias(alias)
+
+	return aliasTable
 }
 
-var (
-{{- range .Columns}}
-	{{.ToGoVarName}} = sqlbuilder.IntColumn("{{.Name}}", {{if .IsNullable}}sqlbuilder.Nullable{{else}}sqlbuilder.NotNullable{{end}})
-{{- end}}
-)
 `
 
 var DataModelTemplate = `package model

sqlbuilder/column.go

@@ -27,6 +27,7 @@ type Column interface {
 	setTableName(table string) error
 
 	Eq(rhs Expression) BoolExpression
+	Neq(rhs Expression) BoolExpression
 
 	Gte(rhs Expression) BoolExpression
 	GteLiteral(rhs interface{}) BoolExpression
@@ -109,6 +110,10 @@ func (c *baseColumn) Eq(rhs Expression) BoolExpression {
 	return Eq(c, rhs)
 }
 
+func (c *baseColumn) Neq(rhs Expression) BoolExpression {
+	return Neq(c, rhs)
+}
+
 func (c *baseColumn) Gte(rhs Expression) BoolExpression {
 	return Gte(c, rhs)
 }
@@ -198,7 +203,7 @@ type IntegerColumn struct {
 
 // Representation of any integer column
 // This function will panic if name is not valid
-func IntColumn(name string, nullable NullableColumn) NonAliasColumn {
+func IntColumn(name string, nullable NullableColumn) *IntegerColumn {
 	if !validIdentifierName(name) {
 		panic("Invalid column name in int column")
 	}

sqlbuilder/table.go

@@ -5,7 +5,6 @@ package sqlbuilder
 import (
 	"bytes"
 	"fmt"
-
 	"github.com/dropbox/godropbox/errors"
 )
 
@@ -85,6 +84,7 @@ func NewTable(schemaName, name string, columns ...NonAliasColumn) *Table {
 type Table struct {
 	schemaName   string
 	name         string
+	alias        string
 	columns      []NonAliasColumn
 	columnLookup map[string]NonAliasColumn
 	// If not empty, the name of the index to force
@@ -119,6 +119,17 @@ func (t *Table) Projections() []Projection {
 	return result
 }
 
+func (t *Table) SetAlias(alias string) {
+	t.alias = alias
+
+	for _, c := range t.columns {
+		err := c.setTableName(alias)
+		if err != nil {
+			panic(err)
+		}
+	}
+}
+
 // Returns the table's name in the database
 func (t *Table) Name() string {
 	return t.name
@@ -151,6 +162,11 @@ func (t *Table) SerializeSql(out *bytes.Buffer) error {
 	_, _ = out.WriteString(".")
 	_, _ = out.WriteString(t.Name())
 
+	if len(t.alias) > 0 {
+		out.WriteString(" AS ")
+		out.WriteString(t.alias)
+	}
+
 	if t.forcedIndex != "" {
 		if !validIdentifierName(t.forcedIndex) {
 			return errors.Newf("'%s' is not a valid identifier for an index", t.forcedIndex)

tests/generator_test.go

@@ -3,6 +3,7 @@ package tests
 import (
 	"database/sql"
 	"fmt"
+	"github.com/davecgh/go-spew/spew"
 	"github.com/sub0Zero/go-sqlbuilder/generator"
 	"github.com/sub0Zero/go-sqlbuilder/tests/.test_files/dvd_rental/dvds/model"
 	. "github.com/sub0Zero/go-sqlbuilder/tests/.test_files/dvd_rental/dvds/table"
@@ -290,6 +291,42 @@ func TestSelectFullCrossJoin(t *testing.T) {
 
 	assert.NilError(t, err)
 }
+
+func TestSelectSelfJoin(t *testing.T) {
+
+	f1 := Film.As("f1")
+
+	//spew.Dump(f1)
+	f2 := Film.As("f2")
+
+	query := f1.
+		InnerJoinOn(f2, f1.FilmID.Neq(f2.FilmID).And(f1.Length.Eq(f2.Length))).
+		Select(f1.AllColumns, f2.AllColumns).
+		OrderBy(f1.FilmID)
+
+	queryStr, err := query.String()
+
+	assert.NilError(t, err)
+
+	fmt.Println(queryStr)
+
+	type F1 model.Film
+	type F2 model.Film
+
+	theSameLengthFilms := []struct {
+		F1 F1
+		F2 F2
+	}{}
+
+	err = query.Execute(db, &theSameLengthFilms)
+
+	assert.NilError(t, err)
+
+	spew.Dump(theSameLengthFilms[0])
+
+	assert.Equal(t, len(theSameLengthFilms), 6972)
+}
+
 func int32Ptr(i int32) *int32 {
 	return &i
 }