OR REPLACE and IF NOT EXISTS in create trigger

Sources/SQLKit/Builders/Implementations/SQLCreateTriggerBuilder.swift

@@ -158,6 +158,22 @@ public final class SQLCreateTriggerBuilder: SQLQueryBuilder {
         self.createTrigger.orderTriggerName = otherTriggerName
         return self
     }
+
+
+    @inlinable
+    @discardableResult
+    public func orReplace(orReplace: Bool = true) -> Self {
+        self.createTrigger.orReplace = orReplace
+        return self
+    }
+
+
+    @inlinable
+    @discardableResult
+    public func ifNotExists(ifNotExists: Bool = true) -> Self {
+        self.createTrigger.ifNotExists = ifNotExists
+        return self
+    }
 }
 
 extension SQLDatabase {

Sources/SQLKit/Database/SQLDialect.swift

@@ -368,6 +368,16 @@ public struct SQLTriggerSyntax: Sendable {
         public static var conditionRequiresParentheses: Self {
             .init(rawValue: 1 << 9)
         }
+
+        /// Indicates support for `OR REPLACE` syntax.
+        public static var supportsOrReplace: Self {
+            .init(rawValue: 1 << 10)
+        }
+
+        /// Indicates support for an `IF NOT EXISTS`  syntax.
+        public static var supportsIfNotExists: Self {
+            .init(rawValue: 1 << 11)
+        }
     }
 
     /// Describes specific feature support for `CREATE TRIGGER` syntax.

Sources/SQLKit/Expressions/Queries/SQLCreateTrigger.swift

@@ -36,6 +36,12 @@ public struct SQLCreateTrigger: SQLExpression {
 
     /// `true` if the new trigger will be a constraint trigger, if supported.
     public var isConstraint: Bool
+
+    /// Include `OR REPLACE` to the trigger syntax.
+    public var orReplace: Bool
+
+    /// Whether to include `IF NOT EXISTS` syntax.
+    public var ifNotExists: Bool
 
     /// The ordering of the trigger's execution relative to the triggering event.
     ///
@@ -122,6 +128,8 @@ public struct SQLCreateTrigger: SQLExpression {
         self.when = when
         self.event = event
         self.isConstraint = false
+        self.orReplace = false
+        self.ifNotExists = false
     }
 
     /// Create a new trigger creation query.
@@ -162,10 +170,23 @@ public struct SQLCreateTrigger: SQLExpression {
             if syntax.contains(.supportsConstraints), self.isConstraint {
                 $0.append("CONSTRAINT")
             }
+
+            if self.orReplace, syntax.contains(.supportsOrReplace) {
+              $0.append("OR REPLACE")
+            }
+
             if let definer = self.definer, syntax.contains(.supportsDefiner) {
                 $0.append("DEFINER =", definer)
             }
-            $0.append("TRIGGER", self.name)
+
+            $0.append("TRIGGER")
+
+            if self.ifNotExists, syntax.contains(.supportsIfNotExists) {
+              $0.append("IF NOT EXISTS")
+            }
+
+            $0.append(self.name)
+
             $0.append(self.when, self.event)
             if let columns = self.columns, !columns.isEmpty, syntax.contains(.supportsUpdateColumns) {
                 $0.append("OF", SQLList(columns))

Tests/SQLKitTests/SQLCreateDropTriggerTests.swift

@@ -33,7 +33,7 @@ final class SQLCreateDropTriggerTests: XCTestCase {
     }
 
     func testMySqlTriggerCreates() {
-        self.db._dialect.triggerSyntax = .init(create: [.supportsBody, .supportsOrder, .supportsDefiner, .requiresForEachRow])
+        self.db._dialect.triggerSyntax = .init(create: [.supportsBody, .supportsOrder, .supportsDefiner, .requiresForEachRow, .supportsIfNotExists])
 
         let builder = self.db.create(trigger: "foo", table: "planet", when: .before, event: .insert)
                 .body(self.body.map { SQLRaw($0) })
@@ -44,20 +44,30 @@ final class SQLCreateDropTriggerTests: XCTestCase {
             of: builder,
             is: "CREATE DEFINER = 'foo@bar' TRIGGER ``foo`` BEFORE INSERT ON ``planet`` FOR EACH ROW PRECEDES ``other`` BEGIN \(self.body.joined(separator: " ")) END;"
         )
+        XCTAssertSerialization(
+            of: self.db.create(trigger: "foo", table: "planet", when: .before, event: .insert)
+                .ifNotExists(),
+            is: "CREATE TRIGGER IF NOT EXISTS ``foo`` BEFORE INSERT ON ``planet`` FOR EACH ROW"
+        )
     }
 
     func testSqliteTriggerCreates() {
-        self.db._dialect.triggerSyntax = .init(create: [.supportsBody, .supportsCondition])
+        self.db._dialect.triggerSyntax = .init(create: [.supportsBody, .supportsCondition, .supportsIfNotExists])
         XCTAssertSerialization(
             of: self.db.create(trigger: "foo", table: "planet", when: .before, event: .insert)
                 .body(self.body.map { SQLRaw($0) })
                 .condition("\(ident: "foo") = \(ident: "bar")" as SQLQueryString),
             is: "CREATE TRIGGER ``foo`` BEFORE INSERT ON ``planet`` WHEN ``foo`` = ``bar`` BEGIN \(self.body.joined(separator: " ")) END;"
         )
+        XCTAssertSerialization(
+            of: self.db.create(trigger: "foo", table: "planet", when: .before, event: .insert)
+                .ifNotExists(),
+            is: "CREATE TRIGGER IF NOT EXISTS ``foo`` BEFORE INSERT ON ``planet``"
+        )
     }
 
     func testPostgreSqlTriggerCreates() {
-        self.db._dialect.triggerSyntax = .init(create: [.supportsForEach, .postgreSQLChecks, .supportsCondition, .conditionRequiresParentheses, .supportsConstraints])
+        self.db._dialect.triggerSyntax = .init(create: [.supportsForEach, .postgreSQLChecks, .supportsCondition, .conditionRequiresParentheses, .supportsConstraints, .supportsOrReplace])
         XCTAssertSerialization(
             of: self.db.create(trigger: "foo", table: "planet", when: .after, event: .insert)
                 .each(.row)
@@ -80,6 +90,10 @@ final class SQLCreateDropTriggerTests: XCTestCase {
                 .procedure("qwer"),
             is: "CREATE TRIGGER ``foo`` INSTEAD OF UPDATE ON ``planet`` FOR EACH ROW EXECUTE PROCEDURE ``qwer``"
         )
+        XCTAssertSerialization(
+            of: self.db.create(trigger: "foo", table: "planet", when: .before, event: .insert)
+                .orReplace(),
+            is: "CREATE OR REPLACE TRIGGER ``foo`` BEFORE INSERT ON ``planet``")
     }
 
     func testPostgreSqlTriggerCreateWithColumns() {