Check constraint backend (#9)

Backend Support for Check Constraint

webv2/api/schema.go

@@ -631,6 +631,91 @@ func (expressionVerificationHandler *ExpressionsVerificationHandler) VerifyCheck
 	json.NewEncoder(w).Encode(hasErrorOccurred)
 }
 
+// UpdateCheckConstraint processes the request to update spanner table check constraints, ensuring session and schema validity, and responds with the updated conversion metadata.
+func UpdateCheckConstraint(w http.ResponseWriter, r *http.Request) {
+	tableId := r.FormValue("table")
+	reqBody, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		http.Error(w, fmt.Sprintf("Body Read Error : %v", err), http.StatusInternalServerError)
+	}
+	sessionState := session.GetSessionState()
+	if sessionState.Conv == nil || sessionState.Driver == "" {
+		http.Error(w, fmt.Sprintf("Schema is not converted or Driver is not configured properly. Please retry converting the database to Spanner."), http.StatusNotFound)
+		return
+	}
+	sessionState.Conv.ConvLock.Lock()
+	defer sessionState.Conv.ConvLock.Unlock()
+
+	newCKs := []ddl.CheckConstraint{}
+	if err = json.Unmarshal(reqBody, &newCKs); err != nil {
+		http.Error(w, fmt.Sprintf("Request Body parse error : %v", err), http.StatusBadRequest)
+		return
+	}
+
+	sp := sessionState.Conv.SpSchema[tableId]
+	sp.CheckConstraints = newCKs
+	sessionState.Conv.SpSchema[tableId] = sp
+	session.UpdateSessionFile()
+
+	convm := session.ConvWithMetadata{
+		SessionMetadata: sessionState.SessionMetadata,
+		Conv:            *sessionState.Conv,
+	}
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(convm)
+}
+
+func doesNameExist(spcks []ddl.CheckConstraint, targetName string) bool {
+	for _, spck := range spcks {
+		if strings.Contains(spck.Expr, targetName) {
+			return true
+		}
+	}
+	return false
+}
+
+// ValidateCheckConstraint verifies if the type of a database column has been altered and add an error if a change is detected.
+func ValidateCheckConstraint(w http.ResponseWriter, r *http.Request) {
+	sessionState := session.GetSessionState()
+	if sessionState.Conv == nil || sessionState.Driver == "" {
+		http.Error(w, fmt.Sprintf("Schema is not converted or Driver is not configured properly. Please retry converting the database to Spanner."), http.StatusNotFound)
+		return
+	}
+	sessionState.Conv.ConvLock.Lock()
+	defer sessionState.Conv.ConvLock.Unlock()
+
+	sp := sessionState.Conv.SpSchema
+	srcschema := sessionState.Conv.SrcSchema
+	flag := true
+	var schemaIssue []internal.SchemaIssue
+
+	for _, src := range srcschema {
+		for _, col := range sp[src.Id].ColDefs {
+			if len(sp[src.Id].CheckConstraints) > 0 {
+				spType := col.T.Name
+				srcType := srcschema[src.Id].ColDefs[col.Id].Type
+				actualType := mysqlDefaultTypeMap[srcType.Name]
+				if actualType.Name != spType {
+					columnName := sp[src.Id].ColDefs[col.Id].Name
+					spcks := sp[src.Id].CheckConstraints
+					if doesNameExist(spcks, columnName) {
+						flag = false
+						schemaIssue = sessionState.Conv.SchemaIssues[src.Id].ColumnLevelIssues[col.Id]
+						if !utilities.IsSchemaIssuePresent(schemaIssue, internal.TypeMismatch) {
+							schemaIssue = append(schemaIssue, internal.TypeMismatch)
+						}
+						sessionState.Conv.SchemaIssues[src.Id].ColumnLevelIssues[col.Id] = schemaIssue
+						break
+					}
+				}
+			}
+		}
+	}
+
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(flag)
+}
+
 // renameForeignKeys checks the new names for spanner name validity, ensures the new names are already not used by existing tables
 // secondary indexes or foreign key constraints. If above checks passed then foreignKey renaming reflected in the schema else appropriate
 // error thrown.