Merge pull request #10 from sschonss/select-where

Select where with =

commands/commands.go

@@ -89,6 +89,11 @@ func InsertInto(command string) {
 }
 
 func SelectFrom(command string) {
+	if strings.Contains(command, "where") {
+		SelectWhere(command)
+		return
+	}
+
 	if strings.Contains(command, "*") {
 		SelectAllFrom(command)
 		return
@@ -141,11 +146,143 @@ func SelectFrom(command string) {
 			}
 		}
 	}
+}
+
+func SelectWhere(command string) {
+	if strings.Contains(command, "*") {
+		SelectAllFromWhere(command)
+		return
+	}
+
+	arrayColumns := strings.Split(command, " ")[1]
+	arrayColumns = strings.Split(arrayColumns, "from")[0]
+	arrayColumns = strings.Replace(arrayColumns, " ", "", -1)
+	arrayColumns = strings.Split(arrayColumns, ",")[0]
+
+	fmt.Println("Colunas: " + arrayColumns)
+
+	table := strings.Split(command, " ")[3]
+
+	if _, err := os.Stat("data/" + table + ".csv"); os.IsNotExist(err) {
+		fmt.Println("Tabela não existe")
+		return
+	}
+
+	file, err := os.Open("data/" + table + ".csv")
+	if err != nil {
+		fmt.Println("Erro ao abrir arquivo")
+		return
+	}
+
+	defer file.Close()
+
+	fmt.Println("Tabela: " + table)
+
+	var columnsTable string
+	fmt.Fscanf(file, "%s\n", &columnsTable)
+	columnsTableArray := strings.Split(columnsTable, ";")
+
+	for i := 0; i < len(columnsTableArray); i++ {
+		if columnsTableArray[i] == arrayColumns {
+			fmt.Println(columnsTableArray[i])
+		}
+	}
+
+	operadores := []string{"=", ">", "<", ">=", "<=", "<>"}
+	conditions := strings.Split(command, "where")[1]
+	conditions = strings.Replace(conditions, " ", "", -1)
+	conditions = strings.Replace(conditions, "(", "", -1)
+	conditions = strings.Replace(conditions, ")", "", -1)
+	conditions = strings.Replace(conditions, ";", "", -1)
+	conditions_array := strings.Split(conditions, "and")
+
+	var operador string
+
+	for i := 0; i < len(operadores); i++ {
+		if strings.Contains(conditions_array[0], operadores[i]) {
+			operador = operadores[i]
+		}
+	}
 
+	valor := strings.Split(conditions_array[0], operador)[1]
+	valor = strings.Replace(valor, " ", "", -1)
 
+	var line string
+	for {
+		_, err := fmt.Fscanf(file, "%s\n", &line)
+		if err != nil {
+			break
+		}
+
+		if operador == "=" {
+			if strings.Contains(line, valor) {
+				lineArray := strings.Split(line, ";")
+				for i := 0; i < len(lineArray); i++ {
+					if columnsTableArray[i] == arrayColumns {
+						fmt.Println(lineArray[i])
+					}
+				}
+			}
+		}
+	}
 }
 
+func SelectAllFromWhere(command string)  {
+	table := strings.Split(command, " ")[3]
+
+	if _, err := os.Stat("data/" + table + ".csv"); os.IsNotExist(err) {
+		fmt.Println("Tabela não existe")
+		return
+	}
+
+	file, err := os.Open("data/" + table + ".csv")
+	if err != nil {
+		fmt.Println("Erro ao abrir arquivo")
+		return
+	}
+
+	defer file.Close()
+
+	fmt.Println("Tabela: " + table)
+	fmt.Println("")
+	var columns string
+	fmt.Fscanf(file, "%s\n", &columns)
+	columns = strings.Replace(columns, ";", " | ", -1)
+	fmt.Println(columns)
+
+	operadores := []string{"=", ">", "<", ">=", "<=", "<>"}
+	conditions := strings.Split(command, "where")[1]
+	conditions = strings.Replace(conditions, " ", "", -1)
+	conditions = strings.Replace(conditions, "(", "", -1)
+	conditions = strings.Replace(conditions, ")", "", -1)
+	conditions = strings.Replace(conditions, ";", "", -1)
+	conditions_array := strings.Split(conditions, "and")
+
+	var operador string
+	for i := 0; i < len(operadores); i++ {
+		if strings.Contains(conditions_array[0], operadores[i]) {
+			operador = operadores[i]
+		}
+	}
+
+	valor := strings.Split(conditions_array[0], operador)[1]
+	valor = strings.Replace(valor, " ", "", -1)
 
+	var line string
+	for {
+		_, err := fmt.Fscanf(file, "%s\n", &line)
+		if err != nil {
+			break
+		}
+
+		if operador == "=" {
+			if strings.Contains(line, valor) {
+				line = strings.Replace(line, ";", " | ", -1)
+				fmt.Println(line)
+			}
+		}
+	}
+}
 
 func SelectAllFrom(command string) {
 

data/config.txt

@@ -0,0 +1,2 @@
+user:root
+password:root

data/users.csv

@@ -0,0 +1,3 @@
+id;nome
+1;luiz
+20;joao

database/database.go

@@ -89,6 +89,22 @@ func (Database) LoadConfig() (string, string) {
 	return user, password
 }
 
+func CheckExisteDirData() bool {
+	_, err := os.Stat("data")
+	if os.IsNotExist(err) {
+		return false
+	} else {
+		return true
+	}
+}
+
+func CreateDirData() {
+	err := os.Mkdir("data", 0755)
+	if err != nil {
+		fmt.Println("Erro ao criar diretório data")
+	}
+}
+
 func (Database) CheckConfig() bool {
 	_, err := os.Stat("data/config.txt")
 	if os.IsNotExist(err) {

main.go

@@ -10,8 +10,16 @@ func main() {
 
 	var db database.Database
 
+	dirData := database.CheckExisteDirData()
+	if !dirData {
+		fmt.Println("Diretório data não encontrado.")
+		fmt.Println("Criando diretório data...")
+		database.CreateDirData()
+		fmt.Println("Diretório data criado com sucesso.")
+	}
+
 	config := db.CheckConfig()
-	if config == true {
+	if config {
 		fmt.Println("Configurações encontradas.")
 		fmt.Println("Digite o usuário e a senha para carregar as configurações.")
 		fmt.Print("Usuário: ")
@@ -20,7 +28,7 @@ func main() {
 		password := database.GetUserInput()
 		valid := db.CheckUser(user, password)
 		count_try := 0
-		for valid == false {
+		for !valid {
 			count_try++
 			if count_try > 2 {
 				fmt.Println("Número de tentativas excedido.")