Add create table (#26)

* Add CreateTable in postgres deparser * Add tests: Postgres Deparser CreateTable
migratemgr8 · May 23, 2022 · 4a7c1d2 · 4a7c1d2
1 parent b4a51c0
commit 4a7c1d2
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Showing 2 changed files with 114 additions and 5 deletions.
diff --git a/drivers/postgres/deparser.go b/drivers/postgres/deparser.go
@@ -2,15 +2,71 @@ package postgres
 
 import (
 	"fmt"
+	"sort"
 
 	"github.com/kenji-yamane/mgr8/domain"
 )
 
 type deparser struct { }
 
+func inStringList(stringList []string, needle string) bool {
+	isIn := false
+	for _, s := range stringList {
+		if needle == s {
+			isIn = true
+		}
+	}
+	return isIn
+}
+
+func hasSingleArg(datatype string) bool {
+	singleArgTypes := []string{"char", "varchar", "bit", "varbit", "time", "timestamp"}
+	if inStringList(singleArgTypes, datatype) {
+		return true
+	} else {
+		return false
+	}
+}
+
+func hasDoubleArg(datatype string) bool {
+	doubleArgTypes := []string{"decimal", "numeric"}
+	if inStringList(doubleArgTypes, datatype) {
+		return true
+	}	else {
+		return false
+	}
+}
+
 func (d *deparser) CreateTable(table *domain.Table) string {
-	// TODO: how to mount this string?
-	return ""
+ 	statement := fmt.Sprintf("CREATE TABLE %s (\n", table.Name)
+
+	columnKeys := []string{}
+	for columnName, _ := range table.Columns {
+		columnKeys = append(columnKeys, columnName)
+	}
+	sort.Strings(columnKeys)
+
+	for _, key := range columnKeys {
+		column := table.Columns[key]
+
+		statement = statement + fmt.Sprintf("%s %s", key, column.Datatype)
+
+		if hasSingleArg(column.Datatype) {
+			statement = statement + fmt.Sprintf("(%d)", column.Parameters["size"])
+		} else if hasDoubleArg(column.Datatype) {
+			statement = statement + fmt.Sprintf("(%d,%d)", column.Parameters["precision"], column.Parameters["scale"])
+		}
+
+		if column.IsNotNull {
+			statement = statement + fmt.Sprintf(" NOT NULL")
+		}
+
+		statement = statement + fmt.Sprintf(",\n")
+	}
+
+	statement = statement[0:len(statement) - 2]
+	statement = statement + fmt.Sprintf("\n)")
+	return statement
 }
 
 func (d *deparser) DropTable(tableName string) string {

diff --git a/drivers/postgres/postgres_test.go b/drivers/postgres/postgres_test.go
@@ -8,11 +8,12 @@ import (
 )
 
 var _ = Describe("Postgres Driver", func() {
-	var (
-		subject *postgresDriver
-	)
 
 	Context("Parse Migration", func() {
+		var (
+			subject *postgresDriver
+		)
+
 		BeforeEach(func() {
 			subject = NewPostgresDriver()
 		})
@@ -55,4 +56,56 @@ var _ = Describe("Postgres Driver", func() {
 			})
 		})
 	})
+
+	Context("Deparse Migration", func() {
+		var (
+			subject deparser
+		)
+
+		BeforeEach(func() {
+			subject = deparser{}
+		})
+
+		When("Table has 1 as maximum argument in data type", func() {
+			It("Generate CREATE TABLE statement", func() {
+				table := &domain.Table{
+					Name: "users",
+					Columns: map[string]*domain.Column{
+						"social_number": {Datatype: "varchar", IsNotNull: false, Parameters: map[string]interface{}{"size": int32(9)}},
+						"favorite_number": {Datatype: "bit", IsNotNull: false, Parameters: map[string]interface{}{"size": int32(6)}},
+						"size":          {Datatype: "int4", IsNotNull: false, Parameters: map[string]interface{}{}},
+					},
+				}
+
+				statement := subject.CreateTable(table)
+				answer := `CREATE TABLE users (
+favorite_number bit(6),
+size int4,
+social_number varchar(9)
+)`
+				Expect(statement).To(Equal(answer))
+			})
+		})
+
+		When("Table has 2 as maximum argument in data type", func() {
+			It("Generate CREATE TABLE statement", func() {
+				table := &domain.Table{
+					Name: "users",
+					Columns: map[string]*domain.Column{
+						"area": {Datatype: "decimal", IsNotNull: false, Parameters: map[string]interface{}{"precision": int32(9), "scale": int32(1)}},
+						"perimeter": {Datatype: "numeric", IsNotNull: false, Parameters: map[string]interface{}{"precision": int32(6), "scale": int32(4)}},
+						"name":          {Datatype: "char", IsNotNull: false, Parameters: map[string]interface{}{"size": int32(10)}},
+					},
+				}
+
+				statement := subject.CreateTable(table)
+				answer := `CREATE TABLE users (
+area decimal(9,1),
+name char(10),
+perimeter numeric(6,4)
+)`
+				Expect(statement).To(Equal(answer))
+			})
+		})
+	})
 })