Added enum for SQLx Error and basic functions for it

src/error.rs

@@ -144,12 +144,13 @@ where
 #[derive(Error, Debug, PartialEq, Eq)]
 #[non_exhaustive]
 pub enum SqlErr {
+    // string stored in error is a placebo,
     /// error for duplicate record in unique field or primary key field
-    #[error("Unique Constraint Violated")]
-    UniqueConstraintViolation,
+    #[error("Unique Constraint Violated: {0}")]
+    UniqueConstraintViolation(String),
     /// error for Foreign key constraint
-    #[error("Foreign Key Constraint Violated")]
-    ForeignKeyConstraintViolation,
+    #[error("Foreign Key Constraint Violated: {0}")]
+    ForeignKeyConstraintViolation(String),
 }
 
 #[allow(dead_code)]
@@ -181,7 +182,9 @@ impl DbErr {
                         // 1169 Can't write, because of unique constraint, to table '%s'
                         // 1586 Duplicate entry '%s' for key '%s'
                         1022 | 1062 | 1169 | 1586 => {
-                            return Some(SqlErr::UniqueConstraintViolation)
+                            return Some(SqlErr::UniqueConstraintViolation(String::from(
+                                e.message(),
+                            )))
                         }
                         // 1216 Cannot add or update a child row: a foreign key constraint fails
                         // 1217 Cannot delete or update a parent row: a foreign key constraint fails
@@ -191,7 +194,9 @@ impl DbErr {
                         // 1761 Foreign key constraint for table '%s', record '%s' would lead to a duplicate entry in table '%s', key '%s'
                         // 1762 Foreign key constraint for table '%s', record '%s' would lead to a duplicate entry in a child table
                         1216 | 1217 | 1451 | 1452 | 1557 | 1761 | 1762 => {
-                            return Some(SqlErr::ForeignKeyConstraintViolation)
+                            return Some(SqlErr::ForeignKeyConstraintViolation(String::from(
+                                e.message(),
+                            )))
                         }
                         _ => return None,
                     }
@@ -201,8 +206,16 @@ impl DbErr {
                     .is_some()
                 {
                     match _error_code_expanded {
-                        "23505" => return Some(SqlErr::UniqueConstraintViolation),
-                        "23503" => return Some(SqlErr::ForeignKeyConstraintViolation),
+                        "23505" => {
+                            return Some(SqlErr::UniqueConstraintViolation(String::from(
+                                e.message(),
+                            )))
+                        }
+                        "23503" => {
+                            return Some(SqlErr::ForeignKeyConstraintViolation(String::from(
+                                e.message(),
+                            )))
+                        }
                         _ => return None,
                     }
                 }
@@ -211,8 +224,16 @@ impl DbErr {
                     match _error_code_expanded {
                         // error code 1555 refers to the primary key's unique constraint violation
                         // error code 2067 refers to the UNIQUE unique constraint violation
-                        "1555" | "2067" => return Some(SqlErr::UniqueConstraintViolation),
-                        "787" => return Some(SqlErr::ForeignKeyConstraintViolation),
+                        "1555" | "2067" => {
+                            return Some(SqlErr::UniqueConstraintViolation(String::from(
+                                e.message(),
+                            )))
+                        }
+                        "787" => {
+                            return Some(SqlErr::ForeignKeyConstraintViolation(String::from(
+                                e.message(),
+                            )))
+                        }
                         _ => return None,
                     }
                 }

tests/sql_err_tests.rs

@@ -2,7 +2,10 @@ pub mod common;
 pub use common::{bakery_chain::*, setup::*, TestContext};
 use pretty_assertions::assert_eq;
 use rust_decimal_macros::dec;
-pub use sea_orm::{entity::*, error::*, tests_cfg, DatabaseConnection, EntityName, ExecResult};
+use sea_orm::ConnectionTrait;
+pub use sea_orm::{
+    entity::*, error::*, tests_cfg, DatabaseConnection, DbBackend, EntityName, ExecResult,
+};
 use uuid::Uuid;
 
 #[sea_orm_macros::test]
@@ -39,7 +42,21 @@ pub async fn test_error(db: &DatabaseConnection) {
         .await
         .expect_err("inserting should fail due to duplicate primary key");
 
-    assert_eq!(error.sql_err(), Some(SqlErr::UniqueConstraintViolation));
+    let mut error_message: &str = "";
+    if db.get_database_backend() == DbBackend::MySql {
+        error_message = "Duplicate entry '1' for key 'cake.PRIMARY'"
+    } else if db.get_database_backend() == DbBackend::Postgres {
+        error_message = "duplicate key value violates unique constraint \"cake_pkey\""
+    } else if db.get_database_backend() == DbBackend::Sqlite {
+        error_message = "UNIQUE constraint failed: cake.id"
+    }
+
+    assert_eq!(
+        error.sql_err(),
+        Some(SqlErr::UniqueConstraintViolation(String::from(
+            error_message
+        )))
+    );
 
     let fk_cake = cake::ActiveModel {
         name: Set("fk error Cake".to_owned()),
@@ -55,8 +72,18 @@ pub async fn test_error(db: &DatabaseConnection) {
         .await
         .expect_err("create foreign key should fail with non-primary key");
 
+    if db.get_database_backend() == DbBackend::MySql {
+        error_message = "Cannot add or update a child row: a foreign key constraint fails (`bakery_chain_sql_err_tests`.`cake`, CONSTRAINT `fk-cake-bakery_id` FOREIGN KEY (`bakery_id`) REFERENCES `bakery` (`id`) ON DELETE CASCADE ON UPDATE CASCADE)"
+    } else if db.get_database_backend() == DbBackend::Postgres {
+        error_message = "insert or update on table \"cake\" violates foreign key constraint \"fk-cake-bakery_id\""
+    } else if db.get_database_backend() == DbBackend::Sqlite {
+        error_message = "FOREIGN KEY constraint failed"
+    }
+
     assert_eq!(
         fk_error.sql_err(),
-        Some(SqlErr::ForeignKeyConstraintViolation)
+        Some(SqlErr::ForeignKeyConstraintViolation(String::from(
+            error_message
+        )))
     );
 }