Merge pull request #3 from aldy505/feat/upsert

Feat/upsert (WIP)

README.md

@@ -2,7 +2,7 @@
 
 [![Go Reference](https://pkg.go.dev/badge/github.com/aldy505/bob.svg)](https://pkg.go.dev/github.com/aldy505/bob) [![Go Report Card](https://goreportcard.com/badge/github.com/aldy505/bob)](https://goreportcard.com/report/github.com/aldy505/bob) ![GitHub](https://img.shields.io/github/license/aldy505/bob) [![CodeFactor](https://www.codefactor.io/repository/github/aldy505/bob/badge)](https://www.codefactor.io/repository/github/aldy505/bob) [![codecov](https://codecov.io/gh/aldy505/bob/branch/master/graph/badge.svg?token=Noeexg5xEJ)](https://codecov.io/gh/aldy505/bob) [![Codacy Badge](https://app.codacy.com/project/badge/Grade/9b78970127c74c1a923533e05f65848d)](https://www.codacy.com/gh/aldy505/bob/dashboard?utm_source=github.com&utm_medium=referral&utm_content=aldy505/bob&utm_campaign=Badge_Grade) [![Build test](https://github.com/aldy505/bob/actions/workflows/build.yml/badge.svg)](https://github.com/aldy505/bob/actions/workflows/build.yml) [![Test and coverage](https://github.com/aldy505/bob/actions/workflows/coverage.yml/badge.svg)](https://github.com/aldy505/bob/actions/workflows/coverage.yml)
 
-Think of this as an extension of [Squirrel](https://github.com/Masterminds/squirrel) with functionability like [Knex](https://knexjs.org/). I still use Squirrel for other types of queries (insert, select, and all that), but I needed some SQL builder for create table and some other stuffs.
+Think of this as an extension of [Squirrel](https://github.com/Masterminds/squirrel) with functionability like [Knex](https://knexjs.org/). I still use Squirrel for other types of queries (insert, select, and all that), but I needed some SQL builder for create table and some other stuffs. Including database creation & upsert.
 
 Oh, and of course, heavily inspired by [Bob the Builder](https://en.wikipedia.org/wiki/Bob_the_Builder).
 
@@ -116,6 +116,44 @@ func main() {
 }
 ```
 
+### Upsert
+
+```go
+func main() {
+  sql, args, err := bob.
+    // Notice that you should give database dialect on the second params.
+    // Available database dialect are MySQL, PostgreSQL, SQLite, and MSSQL.
+    Upsert("users", bob.MySQL).
+    Columns("name", "email", "age").
+    // You could do multiple Values() call, but I'd suggest to not do it.
+    // Because this is an upsert function, not an insert one.
+    Values("Thomas Mueler", "tmueler@something.com", 25).
+    Replace("age", 25).
+    PlaceholderFormat(bob.Question).
+    ToSql()
+
+  // Another example for PostgreSQL
+  sql, args, err = bob.
+    Upsert("users", bob.PostgreSQL).
+    Columns("name", "email", "age").
+    Values("Billy Urtha", "billu@something.com", 30).
+    Key("email").
+    Replace("age", 40).
+    PlaceholderFormat(bob.Dollar).
+    ToSql()
+  
+  // One more time, for MSSQL / SQL Server.
+  sql, args, err = bob.
+    Upsert("users", bob.MSSQL).
+    Columns("name", "email", "age").
+    Values("George Rust", "georgee@something.com", 19).
+    Key("email", "georgee@something.com").
+    Replace("age", 18).
+    PlaceholderFormat(bob.AtP).
+    ToSql()
+}
+```
+
 ### Placeholder format / Dialect
 
 Default placeholder is a question mark (MySQL-like). If you want to change it, simply use something like this:
@@ -222,12 +260,12 @@ func main() {
 * `bob.DropTableIfExists(tableName)` - Drop a table if exists (`drop table if exists "users"`)
 * `bob.RenameTable(currentTable, desiredName)` - Rename a table (`rename table "users" to "people"`)
 * `bob.Truncate(tableName)` - Truncate a table (`truncate "users"`)
+* `bob.Upsert(tableName, dialect)` - UPSERT function (`insert into "users" ("name", "email") values (?, ?) on duplicate key update email = ?`)
 
 ### TODO
 
 Meaning these are some ideas for the future development of Bob.
 
-* `bob.Upsert(tableName)` - UPSERT function (`insert into "users" ("name", "email") values (?, ?) on duplicate key update email = ?`)
 * `bob.ExecWith()` - Just like Squirrel's [ExecWith](https://pkg.go.dev/github.com/Masterminds/squirrel?utm_source=godoc#ExecWith)
 * `bob.Count(tableName, columnName)` - Count query (`select count("active") from "users"`)
 

bob.go

@@ -8,9 +8,20 @@ import (
 
 // ErrEmptyTable is a common database/sql error if a table is empty or no rows is returned by the query.
 var ErrEmptyTable = errors.New("sql: no rows in result set")
+
 // ErrEmptyTable is a common pgx error if a table is empty or no rows is returned by the query.
 var ErrEmptyTablePgx = errors.New("no rows in result set")
 
+// ErrDialectNotSupported tells you whether the dialect is supported or not.
+var ErrDialectNotSupported = errors.New("provided database dialect is not supported")
+
+const (
+	MySQL int = iota
+	PostgreSQL
+	SQLite
+	MSSQL
+)
+
 // BobBuilderType is the type for BobBuilder
 type BobBuilderType builder.Builder
 
@@ -21,12 +32,12 @@ type BobBuilder interface {
 
 // CreateTable creates a table with CreateBuilder interface
 func (b BobBuilderType) CreateTable(table string) CreateBuilder {
-	return CreateBuilder(b).Name(table)
+	return CreateBuilder(b).name(table)
 }
 
 // CreateTableIfNotExists creates a table with CreateBuilder interface, if the table doesn't exists.
 func (b BobBuilderType) CreateTableIfNotExists(table string) CreateBuilder {
-	return CreateBuilder(b).Name(table).IfNotExists()
+	return CreateBuilder(b).name(table).ifNotExists()
 }
 
 // HasTable checks if a table exists with HasBuilder interface
@@ -41,28 +52,49 @@ func (b BobBuilderType) HasColumn(column string) HasBuilder {
 
 // DropTable drops (delete contents & remove) a table from the database.
 func (b BobBuilderType) DropTable(table string) DropBuilder {
-	return DropBuilder(b).DropTable(table)
+	return DropBuilder(b).dropTable(table)
 }
 
 // DropTable drops (delete contents & remove) a table from the database if the table exists.
 func (b BobBuilderType) DropTableIfExists(table string) DropBuilder {
-	return DropBuilder(b).DropTable(table).IfExists()
+	return DropBuilder(b).dropTable(table).ifExists()
 }
 
 // RenameTable simply renames an exisisting table.
 func (b BobBuilderType) RenameTable(from, to string) RenameBuilder {
-	return RenameBuilder(b).From(from).To(to)
+	return RenameBuilder(b).from(from).to(to)
 }
 
 // Truncate performs TRUNCATE function. It deletes all contents from a table but not deleting the table.
 func (b BobBuilderType) Truncate(table string) TruncateBuilder {
-	return TruncateBuilder(b).Truncate(table)
+	return TruncateBuilder(b).truncate(table)
+}
+
+func (b BobBuilderType) Upsert(table string, dialect int) UpsertBuilder {
+	return UpsertBuilder(b).dialect(dialect).into(table)
 }
 
 // BobStmtBuilder is the parent builder for BobBuilderType
 var BobStmtBuilder = BobBuilderType(builder.EmptyBuilder)
 
 // CreateTable creates a table with CreateBuilder interface.
+// Refer to README for available column definition types.
+//
+//      // Note that CREATE TABLE doesn't returns args params.
+//      sql, _, err := bob.
+//        CreateTable("tableName").
+//        // The first parameter is the column's name.
+//        // The second parameters and so on forth are extras.
+//        StringColumn("id", "NOT NULL", "PRIMARY KEY", "AUTOINCREMENT").
+//        StringColumn("email", "NOT NULL", "UNIQUE").
+//        // See the list of available column definition types through pkg.go.dev or README.
+//        TextColumn("password").
+//        // Or add your custom type.
+//        AddColumn(bob.ColumnDef{Name: "tableName", Type: "customType", Extras: []string{"NOT NULL"}}).
+//        ToSql()
+//      if err != nil {
+//      // handle your error
+//      }
 func CreateTable(table string) CreateBuilder {
 	return BobStmtBuilder.CreateTable(table)
 }
@@ -101,3 +133,42 @@ func RenameTable(from, to string) RenameBuilder {
 func Truncate(table string) TruncateBuilder {
 	return BobStmtBuilder.Truncate(table)
 }
+
+// Upsert performs a UPSERT query with specified database dialect.
+// Supported database includes MySQL, PostgreSQL, SQLite and MSSQL.
+//
+//       // MySQL example:
+//       sql, args, err := bob.
+//         // Notice that you should give database dialect on the second params.
+//         // Available database dialect are MySQL, PostgreSQL, SQLite, and MSSQL.
+//         Upsert("users", bob.MySQL).
+//         Columns("name", "email", "age").
+//         // You could do multiple Values() call, but I'd suggest to not do it.
+//         // Because this is an upsert function, not an insert one.
+//         Values("Thomas Mueler", "tmueler@something.com", 25).
+//         Replace("age", 25).
+//         PlaceholderFormat(bob.Question).
+//         ToSql()
+//
+//       // Another example for PostgreSQL:
+//       sql, args, err = bob.
+//         Upsert("users", bob.PostgreSQL).
+//         Columns("name", "email", "age").
+//         Values("Billy Urtha", "billu@something.com", 30).
+//         Key("email").
+//         Replace("age", 40).
+//         PlaceholderFormat(bob.Dollar).
+//         ToSql()
+//
+//       // One more time, for MSSQL / SQL Server:
+//       sql, args, err = bob.
+//         Upsert("users", bob.MSSQL).
+//         Columns("name", "email", "age").
+//         Values("George Rust", "georgee@something.com", 19).
+//         Key("email", "georgee@something.com").
+//         Replace("age", 18).
+//         PlaceholderFormat(bob.AtP).
+//         ToSql()
+func Upsert(table string, dialect int) UpsertBuilder {
+	return BobStmtBuilder.Upsert(table, dialect)
+}

create.go

@@ -27,13 +27,13 @@ func init() {
 	builder.Register(CreateBuilder{}, createData{})
 }
 
-// Name sets the table name
+// name sets the table name
-func (b CreateBuilder) Name(name string) CreateBuilder {
+func (b CreateBuilder) name(name string) CreateBuilder {
 	return builder.Set(b, "TableName", name).(CreateBuilder)
 }
 
-// IfNotExists adds IF NOT EXISTS to the query
+// ifNotExists adds IF NOT EXISTS to the query
-func (b CreateBuilder) IfNotExists() CreateBuilder {
+func (b CreateBuilder) ifNotExists() CreateBuilder {
 	return builder.Set(b, "IfNotExists", true).(CreateBuilder)
 }
 

drop.go

@@ -19,11 +19,11 @@ func init() {
 }
 
 // DropTable sets which table to be dropped
-func (b DropBuilder) DropTable(name string) DropBuilder {
+func (b DropBuilder) dropTable(name string) DropBuilder {
 	return builder.Set(b, "TableName", name).(DropBuilder)
 }
 
-func (b DropBuilder) IfExists() DropBuilder {
+func (b DropBuilder) ifExists() DropBuilder {
 	return builder.Set(b, "IfExists", true).(DropBuilder)
 }
 
@@ -46,7 +46,7 @@ func (d *dropData) ToSql() (sqlStr string, args []interface{}, err error) {
 		sql.WriteString("IF EXISTS ")
 	}
 
-	sql.WriteString("\""+d.TableName+"\";")
+	sql.WriteString("\"" + d.TableName + "\";")
 
 	sqlStr = sql.String()
 	return

drop_test.go

@@ -7,7 +7,7 @@ import (
 )
 
 func TestDrop(t *testing.T) {
-	t.Run("should be able to create regular drop query", func (t *testing.T)  {
+	t.Run("should be able to create regular drop query", func(t *testing.T) {
 		sql, _, err := bob.DropTable("users").ToSql()
 		if err != nil {
 			t.Error(err)

has.go

@@ -8,9 +8,6 @@ import (
 	"github.com/lann/builder"
 )
 
-// TODO - The whole file is a todo
-// Meant to find two things: HasTable and HasColumn(s)
-
 type HasBuilder builder.Builder
 
 type hasData struct {

has_test.go

@@ -1,13 +1,12 @@
 package bob_test
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/aldy505/bob"
 )
 
-// TODO - do more test
-
 func TestHas(t *testing.T) {
 	t.Run("should be able to create a hasTable query", func(t *testing.T) {
 		sql, args, err := bob.HasTable("users").ToSql()
@@ -19,8 +18,8 @@ func TestHas(t *testing.T) {
 		if sql != result {
 			t.Fatal("sql is not equal with result:", sql)
 		}
-
+		argsResult := []interface{}{"users"}
-		if len(args) != 1 {
+		if !reflect.DeepEqual(args, argsResult) {
 			t.Fatal("args is not equal with argsResult:", args)
 		}
 	})
@@ -36,7 +35,8 @@ func TestHas(t *testing.T) {
 			t.Fatal("sql is not equal with result:", sql)
 		}
 
-		if len(args) != 2 {
+		argsResult := []interface{}{"users", "name"}
+		if !reflect.DeepEqual(args, argsResult) {
 			t.Fatal("args is not equal with argsResult:", args)
 		}
 	})
@@ -52,7 +52,8 @@ func TestHas(t *testing.T) {
 			t.Fatal("sql is not equal with result:", sql)
 		}
 
-		if len(args) != 2 {
+		argsResult := []interface{}{"users", "name"}
+		if !reflect.DeepEqual(args, argsResult) {
 			t.Fatal("args is not equal with argsResult:", args)
 		}
 	})
@@ -68,12 +69,13 @@ func TestHas(t *testing.T) {
 			t.Fatal("sql is not equal with result:", sql)
 		}
 
-		if len(args) != 2 {
+		argsResult := []interface{}{"users", "private"}
+		if !reflect.DeepEqual(args, argsResult) {
 			t.Fatal("args is not equal with argsResult:", args)
 		}
 	})
 
-	t.Run("should be able to have a different placeholder", func(t *testing.T) {
+	t.Run("should be able to have a different placeholder - dollar", func(t *testing.T) {
 		sql, args, err := bob.HasTable("users").HasColumn("name").PlaceholderFormat(bob.Dollar).ToSql()
 		if err != nil {
 			t.Fatal(err.Error())
@@ -84,7 +86,8 @@ func TestHas(t *testing.T) {
 			t.Fatal("sql is not equal with result:", sql)
 		}
 
-		if len(args) != 2 {
+		argsResult := []interface{}{"users", "name"}
+		if !reflect.DeepEqual(args, argsResult) {
 			t.Fatal("args is not equal with argsResult:", args)
 		}
 	})

rename.go

@@ -17,13 +17,13 @@ func init() {
 	builder.Register(RenameBuilder{}, renameData{})
 }
 
-// From sets existing table name
+// from sets existing table name
-func (b RenameBuilder) From(name string) RenameBuilder {
+func (b RenameBuilder) from(name string) RenameBuilder {
 	return builder.Set(b, "From", name).(RenameBuilder)
 }
 
-// To sets desired table name
+// to sets desired table name
-func (b RenameBuilder) To(name string) RenameBuilder {
+func (b RenameBuilder) to(name string) RenameBuilder {
 	return builder.Set(b, "To", name).(RenameBuilder)
 }
 
@@ -38,6 +38,6 @@ func (d *renameData) ToSql() (sqlStr string, args []interface{}, err error) {
 	if len(d.From) == 0 || d.From == "" || len(d.To) == 0 || d.To == "" {
 		err = errors.New("rename statement must specify a table")
 	}
-	sqlStr = "RENAME TABLE \""+d.From+"\" TO \""+d.To+"\";"
+	sqlStr = "RENAME TABLE \"" + d.From + "\" TO \"" + d.To + "\";"
 	return
 }

rename_test.go

@@ -7,7 +7,7 @@ import (
 )
 
 func TestRename(t *testing.T) {
-	t.Run("should be able to create rename query", func (t *testing.T)  {
+	t.Run("should be able to create rename query", func(t *testing.T) {
 		sql, _, err := bob.RenameTable("users", "teachers").ToSql()
 		if err != nil {
 			t.Error(err)

truncate.go

@@ -17,7 +17,7 @@ func init() {
 }
 
 // Truncate sets which table to be dropped
-func (b TruncateBuilder) Truncate(name string) TruncateBuilder {
+func (b TruncateBuilder) truncate(name string) TruncateBuilder {
 	return builder.Set(b, "TableName", name).(TruncateBuilder)
 }
 
@@ -32,6 +32,6 @@ func (d *truncateData) ToSql() (sqlStr string, args []interface{}, err error) {
 	if len(d.TableName) == 0 || d.TableName == "" {
 		err = errors.New("truncate statement must specify a table")
 	}
-	sqlStr = "TRUNCATE \""+d.TableName+"\";"
+	sqlStr = "TRUNCATE \"" + d.TableName + "\";"
 	return
 }

truncate_test.go

@@ -7,7 +7,7 @@ import (
 )
 
 func TestTruncate(t *testing.T) {
-	t.Run("should be able to create truncate query", func (t *testing.T)  {
+	t.Run("should be able to create truncate query", func(t *testing.T) {
 		sql, _, err := bob.Truncate("users").ToSql()
 		if err != nil {
 			t.Error(err)

upsert.go

@@ -0,0 +1,193 @@
+package bob
+
+import (
+	"bytes"
+	"errors"
+	"strings"
+
+	"github.com/lann/builder"
+)
+
+type UpsertBuilder builder.Builder
+
+type upsertData struct {
+	Dialect     int
+	Into        string
+	Columns     []string
+	Values      [][]interface{}
+	Key         []interface{}
+	Replace     [][]interface{}
+	Placeholder string
+}
+
+func init() {
+	builder.Register(UpsertBuilder{}, upsertData{})
+}
+
+// dialect specifies database dialect used.
+func (u UpsertBuilder) dialect(db int) UpsertBuilder {
+	return builder.Set(u, "Dialect", db).(UpsertBuilder)
+}
+
+// Table sets which table to be dropped.
+func (u UpsertBuilder) into(name string) UpsertBuilder {
+	return builder.Set(u, "Into", name).(UpsertBuilder)
+}
+
+// Columns sets the columns for the data to be inserted.
+func (u UpsertBuilder) Columns(columns ...string) UpsertBuilder {
+	return builder.Extend(u, "Columns", columns).(UpsertBuilder)
+}
+
+// Values sets the values in relation with the columns.
+// Please not that only string, int, and bool type are supported.
+// Inputting other types other than those might result in your SQL not working properly.
+func (u UpsertBuilder) Values(values ...interface{}) UpsertBuilder {
+	return builder.Append(u, "Values", values).(UpsertBuilder)
+}
+
+// Key specifies which key to be checked on conflict.
+// Must be used on PostgreSQL and SQLite.
+func (u UpsertBuilder) Key(key ...interface{}) UpsertBuilder {
+	var value interface{}
+	column := key[0]
+	if len(key) > 1 && key[0] != nil {
+		value = key[1]
+	} else {
+		value = ""
+	}
+	return builder.Extend(u, "Key", []interface{}{column, value}).(UpsertBuilder)
+}
+
+// Replace sets the column and value respectively for the data to be changed on
+// a specific row.
+func (u UpsertBuilder) Replace(column interface{}, value interface{}) UpsertBuilder {
+	return builder.Append(u, "Replace", []interface{}{column, value}).(UpsertBuilder)
+}
+
+// PlaceholderFormat changes the default placeholder (?) to desired placeholder.
+func (u UpsertBuilder) PlaceholderFormat(f string) UpsertBuilder {
+	return builder.Set(u, "Placeholder", f).(UpsertBuilder)
+}
+
+// ToSql returns 3 variables filled out with the correct values based on bindings, etc.
+func (u UpsertBuilder) ToSql() (string, []interface{}, error) {
+	data := builder.GetStruct(u).(upsertData)
+	return data.ToSql()
+}
+
+// ToSql returns 3 variables filled out with the correct values based on bindings, etc.
+func (d *upsertData) ToSql() (sqlStr string, args []interface{}, err error) {
+	if len(d.Into) == 0 || d.Into == "" {
+		err = errors.New("upsert statements must specify a table")
+		return
+	}
+
+	if len(d.Columns) == 0 || d.Columns[0] == "" {
+		err = errors.New("upsert statement must have at least one column")
+		return
+	}
+
+	if len(d.Values) == 0 {
+		err = errors.New("upsert statements must have at least one set of values")
+		return
+	}
+
+	if len(d.Replace) == 0 {
+		err = errors.New("upsert statement must have at least one key value pair to be replaced")
+		return
+	}
+
+	sql := &bytes.Buffer{}
+
+	if d.Dialect == MSSQL {
+		if len(d.Key) == 0 {
+			err = errors.New("unique key and value must be provided for MS SQL")
+			return
+		}
+
+		sql.WriteString("IF NOT EXISTS (SELECT * FROM \"" + d.Into + "\" WHERE \"" + d.Key[0].(string) + "\" = ?) ")
+		args = append(args, d.Key[1])
+	}
+
+	sql.WriteString("INSERT INTO ")
+	sql.WriteString("\"" + d.Into + "\"")
+	sql.WriteString(" ")
+
+	var columns []string
+	for _, v := range d.Columns {
+		columns = append(columns, "\""+v+"\"")
+	}
+
+	sql.WriteString("(")
+	sql.WriteString(strings.Join(columns, ", "))
+	sql.WriteString(") ")
+
+	sql.WriteString("VALUES ")
+
+	var values []string
+	for i := 0; i < len(d.Values); i++ {
+		var tempValues []string
+		for _, v := range d.Values[i] {
+			args = append(args, v)
+			tempValues = append(tempValues, "?")
+		}
+		values = append(values, "("+strings.Join(tempValues, ", ")+")")
+	}
+
+	sql.WriteString(strings.Join(values, ", "))
+	sql.WriteString(" ")
+
+	var replaces []string
+	for i := 0; i < len(d.Replace); i++ {
+		args = append(args, d.Replace[i][1])
+		replace := "\"" + d.Replace[i][0].(string) + "\" = ?"
+		replaces = append(replaces, replace)
+	}
+
+	if d.Dialect == MySQL {
+		// INSERT INTO table (col) VALUES (values) ON DUPLICATE KEY UPDATE col = value
+
+		sql.WriteString("ON DUPLICATE KEY UPDATE ")
+		sql.WriteString(strings.Join(replaces, ", "))
+	} else if d.Dialect == PostgreSQL || d.Dialect == SQLite {
+		// INSERT INTO players (user_name, age) VALUES('steven', 32) ON CONFLICT(user_name) DO UPDATE SET age=excluded.age;
+
+		if len(d.Key) == 0 {
+			err = errors.New("unique key must be provided for PostgreSQL and SQLite")
+			return
+		}
+
+		sql.WriteString("ON CONFLICT ")
+		sql.WriteString("(\"" + d.Key[0].(string) + "\") ")
+		sql.WriteString("DO UPDATE SET ")
+		sql.WriteString(strings.Join(replaces, ", "))
+
+	} else if d.Dialect == MSSQL {
+		// IF NOT EXISTS (SELECT * FROM dbo.Table1 WHERE ID = @ID)
+		//    INSERT INTO dbo.Table1(ID, Name, ItemName, ItemCatName, ItemQty)
+		//    VALUES(@ID, @Name, @ItemName, @ItemCatName, @ItemQty)
+		// ELSE
+		//    UPDATE dbo.Table1
+		//    SET Name = @Name,
+		//        ItemName = @ItemName,
+		//        ItemCatName = @ItemCatName,
+		//        ItemQty = @ItemQty
+		//    WHERE ID = @ID
+
+		sql.WriteString("ELSE ")
+		sql.WriteString("UPDATE \"" + d.Into + "\" SET ")
+		sql.WriteString(strings.Join(replaces, ", "))
+		sql.WriteString(" WHERE \"" + d.Key[0].(string) + "\" = ?")
+		args = append(args, d.Key[1])
+
+	} else {
+		err = ErrDialectNotSupported
+		return
+	}
+
+	sql.WriteString(";")
+
+	sqlStr = ReplacePlaceholder(sql.String(), d.Placeholder)
+	return
+}

upsert_test.go

@@ -0,0 +1,155 @@
+package bob_test
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/aldy505/bob"
+)
+
+func TestUpsert_MySQL(t *testing.T) {
+	sql, args, err := bob.
+		Upsert("users", bob.MySQL).
+		Columns("name", "email").
+		Values("John Doe", "john@doe.com").
+		Replace("name", "John Does").
+		ToSql()
+	if err != nil {
+		t.Error(err)
+	}
+
+	desiredSql := "INSERT INTO \"users\" (\"name\", \"email\") VALUES (?, ?) ON DUPLICATE KEY UPDATE \"name\" = ?;"
+	desiredArgs := []interface{}{"John Doe", "john@doe.com", "John Does"}
+
+	if sql != desiredSql {
+		t.Error("sql is not the same as result: ", sql)
+	}
+	if !reflect.DeepEqual(args, desiredArgs) {
+		t.Error("args is not the same as result: ", args)
+	}
+}
+
+func TestUpsert_PostgreSQL(t *testing.T) {
+	sql, args, err := bob.
+		Upsert("users", bob.PostgreSQL).
+		Columns("name", "email").
+		Values("John Doe", "john@doe.com").
+		Key("email").
+		Replace("name", "John Does").
+		PlaceholderFormat(bob.Dollar).
+		ToSql()
+	if err != nil {
+		t.Error(err)
+	}
+
+	desiredSql := "INSERT INTO \"users\" (\"name\", \"email\") VALUES ($1, $2) ON CONFLICT (\"email\") DO UPDATE SET \"name\" = $3;"
+	desiredArgs := []interface{}{"John Doe", "john@doe.com", "John Does"}
+
+	if sql != desiredSql {
+		t.Error("sql is not the same as result: ", sql)
+	}
+	if !reflect.DeepEqual(args, desiredArgs) {
+		t.Error("args is not the same as result: ", args)
+	}
+}
+
+func TestUpsert_SQLite(t *testing.T) {
+	sql, args, err := bob.
+		Upsert("users", bob.SQLite).
+		Columns("name", "email").
+		Values("John Doe", "john@doe.com").
+		Key("email").
+		Replace("name", "John Does").
+		PlaceholderFormat(bob.Question).
+		ToSql()
+	if err != nil {
+		t.Error(err)
+	}
+
+	desiredSql := "INSERT INTO \"users\" (\"name\", \"email\") VALUES (?, ?) ON CONFLICT (\"email\") DO UPDATE SET \"name\" = ?;"
+	desiredArgs := []interface{}{"John Doe", "john@doe.com", "John Does"}
+
+	if sql != desiredSql {
+		t.Error("sql is not the same as result: ", sql)
+	}
+	if !reflect.DeepEqual(args, desiredArgs) {
+		t.Error("args is not the same as result: ", args)
+	}
+}
+
+func TestUpsert_MSSQL(t *testing.T) {
+	sql, args, err := bob.
+		Upsert("users", bob.MSSQL).
+		Columns("name", "email").
+		Values("John Doe", "john@doe.com").
+		Key("email", "john@doe.com").
+		Replace("name", "John Does").
+		PlaceholderFormat(bob.AtP).
+		ToSql()
+	if err != nil {
+		t.Error(err)
+	}
+
+	desiredSql := "IF NOT EXISTS (SELECT * FROM \"users\" WHERE \"email\" = @p1) INSERT INTO \"users\" (\"name\", \"email\") VALUES (@p2, @p3) ELSE UPDATE \"users\" SET \"name\" = @p4 WHERE \"email\" = @p5;"
+	desiredArgs := []interface{}{"john@doe.com", "John Doe", "john@doe.com", "John Does", "john@doe.com"}
+
+	if sql != desiredSql {
+		t.Error("sql is not the same as result: ", sql)
+	}
+	if !reflect.DeepEqual(args, desiredArgs) {
+		t.Error("args is not the same as result: ", args)
+	}
+}
+
+func TestUpsert_EmitErrors(t *testing.T) {
+	t.Run("should emit error without table name", func(t *testing.T) {
+		_, _, err := bob.Upsert("", bob.MySQL).ToSql()
+		if err == nil && err.Error() != "upsert statement must specify a table" {
+			t.Error(err)
+		}
+	})
+
+	t.Run("should emit error without columns", func(t *testing.T) {
+		_, _, err := bob.Upsert("users", bob.PostgreSQL).ToSql()
+		if err.Error() != "upsert statement must have at least one column" {
+			t.Error(err)
+		}
+	})
+
+	t.Run("should emit error without values", func(t *testing.T) {
+		_, _, err := bob.Upsert("users", bob.PostgreSQL).Columns("name", "email").ToSql()
+		if err.Error() != "upsert statements must have at least one set of values" {
+			t.Error(err)
+		}
+	})
+
+	t.Run("should emit error without replaces", func(t *testing.T) {
+		_, _, err := bob.Upsert("users", bob.PostgreSQL).Columns("name", "email").Values("James", "james@mail.com").ToSql()
+		if err.Error() != "upsert statement must have at least one key value pair to be replaced" {
+			t.Error(err)
+		}
+	})
+
+	t.Run("should emit error without key and value for mssql", func(t *testing.T) {
+		_, _, err := bob.Upsert("users", bob.MSSQL).Columns("name", "email").Values("James", "james@mail.com").Replace("name", "Thomas").ToSql()
+		if err.Error() != "unique key and value must be provided for MS SQL" {
+			t.Error(err)
+		}
+	})
+
+	t.Run("should emit error without key and value for mssql", func(t *testing.T) {
+		_, _, err := bob.Upsert("users", bob.SQLite).Columns("name", "email").Values("James", "james@mail.com").Replace("name", "Thomas").ToSql()
+		if err.Error() != "unique key must be provided for PostgreSQL and SQLite" {
+			t.Log(err.Error())
+			t.Error(err)
+		}
+	})
+
+	t.Run("should emit error if dialect not supported", func(t *testing.T) {
+		_, _, err := bob.Upsert("users", 100).Columns("name", "email").Values("James", "james@mail.com").Replace("name", "Thomas").ToSql()
+		if err.Error() != "provided database dialect is not supported" {
+			t.Log(err.Error())
+			t.Error(err)
+		}
+	})
+}

util/arguments.go

@@ -2,7 +2,7 @@ package util
 
 // createArgs should create an argument []interface{} for SQL query
 // I'm using the idiot approach for creating args
-func CreateArgs(keys ...string) []interface{} {
+func CreateArgs(keys ...interface{}) []interface{} {
 	var args []interface{}
 	for _, v := range keys {
 		if v == "" {