refactor(error): error handling in database package

- Replace custom error types with string constants for common database errors.
- Simplify the Database struct to include a Reason field for error messages.
- Update Error method to format the error output using the Reason.
- Modify validation error constants for consistency and clarity.

pkg/error/database.go

@@ -1,25 +1,19 @@
 package error
 
-type EntityAlreadyExists struct{}
+import "fmt"
 
-func (e *EntityAlreadyExists) Error() string {
-	return "EntityAlreadyExists error"
+const (
+	EntityAlreadyExists    = "EntityAlreadyExists"
+	NoDataWritten          = "NoDataWritten"
+	NoDataFound            = "NoDataFound"
+	DatabaseIsNotConnected = "database is not connected"
+	DuplicateKey           = "DuplicateKey"
+)
+
+type Database struct {
+	Reason string
 }
 
-type NoDataWritten struct{}
-
-func (e *NoDataWritten) Error() string {
-	return "NoDataWritten error"
-}
-
-type NoDataFound struct{}
-
-func (e *NoDataFound) Error() string {
-	return "NoDataFound error"
-}
-
-type NoRelationCreated struct{}
-
-func (e *NoRelationCreated) Error() string {
-	return "relationship creation error"
+func (e Database) Error() string {
+	return fmt.Sprintf("Database error: %s", e.Reason)
 }

pkg/error/validation.go

@@ -3,11 +3,13 @@ package error
 import "fmt"
 
 const (
-	AnthroveUserIDIsEmpty   = "anthrovePostID cannot be empty"
-	AnthroveUserIDToShort   = "anthrovePostID needs to be 25 characters long"
-	AnthroveSourceIDEmpty   = "anthroveSourceID cannot be empty"
-	AnthroveSourceIDToShort = "anthroveSourceID needs to be 25 characters long"
-	AnthroveTagIDEmpty      = "tagID cannot be empty"
+	UserIDIsEmpty       = "anthrovePostID cannot be empty"
+	UserIDToShort       = "anthrovePostID needs to be 25 characters long"
+	SourceIDEmpty       = "anthroveSourceID cannot be empty"
+	SourceIDToShort     = "anthroveSourceID needs to be 25 characters long"
+	UserSourceIDEmpty   = "anthroveUserSourceID cannot be empty"
+	UserSourceIDToShort = "anthroveUserSourceID needs to be 25 characters long"
+	TagIDEmpty          = "tagID cannot be empty"
 )
 
 type EntityValidationFailed struct {