fix: Update foreign key constraints handling in migration for CurrenciesPegging and CurrenciesInflation

Marechai.Database/Migrations/20200807234824_FixDumpRequiredFields.cs

@@ -1,4 +1,4 @@
-using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Migrations;
 
 namespace Marechai.Database.Migrations
 {
@@ -15,6 +15,46 @@ namespace Marechai.Database.Migrations
             migrationBuilder.AlterColumn<string>("Dumper", "Dumps", nullable: false, oldClrType: typeof(string),
                                                  oldType: "varchar(255) CHARACTER SET utf8mb4", oldNullable: true);
 
+            // MySQL/MariaDB: Disable foreign key checks to allow column modifications
+            migrationBuilder.Sql("SET FOREIGN_KEY_CHECKS=0");
+
+            // Drop foreign key constraints only if they exist before modifying columns to make them nullable
+            migrationBuilder.Sql(@"
+                IF EXISTS (
+                    SELECT 1 FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS 
+                    WHERE CONSTRAINT_SCHEMA = DATABASE() 
+                    AND TABLE_NAME = 'CurrenciesPegging'
+                    AND CONSTRAINT_NAME = 'FK_CurrenciesPegging_Iso4217_SourceCode'
+                )
+                THEN
+                    ALTER TABLE `CurrenciesPegging` DROP FOREIGN KEY `FK_CurrenciesPegging_Iso4217_SourceCode`;
+                END IF;
+            ");
+
+            migrationBuilder.Sql(@"
+                IF EXISTS (
+                    SELECT 1 FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS 
+                    WHERE CONSTRAINT_SCHEMA = DATABASE() 
+                    AND TABLE_NAME = 'CurrenciesPegging'
+                    AND CONSTRAINT_NAME = 'FK_CurrenciesPegging_Iso4217_DestinationCode'
+                )
+                THEN
+                    ALTER TABLE `CurrenciesPegging` DROP FOREIGN KEY `FK_CurrenciesPegging_Iso4217_DestinationCode`;
+                END IF;
+            ");
+
+            migrationBuilder.Sql(@"
+                IF EXISTS (
+                    SELECT 1 FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS 
+                    WHERE CONSTRAINT_SCHEMA = DATABASE() 
+                    AND TABLE_NAME = 'CurrenciesInflation'
+                    AND CONSTRAINT_NAME = 'FK_CurrenciesInflation_Iso4217_CurrencyCode'
+                )
+                THEN
+                    ALTER TABLE `CurrenciesInflation` DROP FOREIGN KEY `FK_CurrenciesInflation_Iso4217_CurrencyCode`;
+                END IF;
+            ");
+
             migrationBuilder.AlterColumn<string>("SourceCode", "CurrenciesPegging", nullable: true,
                                                  oldClrType: typeof(string),
                                                  oldType: "varchar(3) CHARACTER SET utf8mb4");
@@ -26,6 +66,9 @@ namespace Marechai.Database.Migrations
             migrationBuilder.AlterColumn<string>("CurrencyCode", "CurrenciesInflation", nullable: true,
                                                  oldClrType: typeof(string),
                                                  oldType: "varchar(3) CHARACTER SET utf8mb4");
+
+            // Re-enable foreign key checks
+            migrationBuilder.Sql("SET FOREIGN_KEY_CHECKS=1");
         }
 
         protected override void Down(MigrationBuilder migrationBuilder)
@@ -39,6 +82,9 @@ namespace Marechai.Database.Migrations
             migrationBuilder.AlterColumn<string>("Dumper", "Dumps", "varchar(255) CHARACTER SET utf8mb4",
                                                  nullable: true, oldClrType: typeof(string));
 
+            // MySQL/MariaDB: Disable foreign key checks to allow column modifications
+            migrationBuilder.Sql("SET FOREIGN_KEY_CHECKS=0");
+
             migrationBuilder.AlterColumn<string>("SourceCode", "CurrenciesPegging", "varchar(3) CHARACTER SET utf8mb4",
                                                  nullable: false, oldClrType: typeof(string), oldNullable: true);
 
@@ -49,6 +95,34 @@ namespace Marechai.Database.Migrations
             migrationBuilder.AlterColumn<string>("CurrencyCode", "CurrenciesInflation",
                                                  "varchar(3) CHARACTER SET utf8mb4", nullable: false,
                                                  oldClrType: typeof(string), oldNullable: true);
+
+            // Recreate foreign key constraints for Down operation (when reverting to NOT NULL)
+            migrationBuilder.AddForeignKey(
+                name: "FK_CurrenciesPegging_Iso4217_SourceCode",
+                table: "CurrenciesPegging",
+                column: "SourceCode",
+                principalTable: "Iso4217",
+                principalColumn: "Code",
+                onDelete: ReferentialAction.Cascade);
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_CurrenciesPegging_Iso4217_DestinationCode",
+                table: "CurrenciesPegging",
+                column: "DestinationCode",
+                principalTable: "Iso4217",
+                principalColumn: "Code",
+                onDelete: ReferentialAction.Cascade);
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_CurrenciesInflation_Iso4217_CurrencyCode",
+                table: "CurrenciesInflation",
+                column: "CurrencyCode",
+                principalTable: "Iso4217",
+                principalColumn: "Code",
+                onDelete: ReferentialAction.Cascade);
+
+            // Re-enable foreign key checks
+            migrationBuilder.Sql("SET FOREIGN_KEY_CHECKS=1");
         }
     }
 }