From b96fbd9b674d32c9ffd30b8f01c416404fd197a8 Mon Sep 17 00:00:00 2001
From: Lukas Eder <lukas.eder@gmail.com>
Date: Wed, 6 May 2020 09:24:09 +0200
Subject: [PATCH] [jOOQ/jOOQ#10160] Add support for MySQL's IF() function

---
 jOOQ/src/main/java/org/jooq/impl/DSL.java     | 46 ++++++++++++++++---
 jOOQ/src/main/java/org/jooq/impl/Iif.java     | 14 +++---
 jOOQ/src/main/java/org/jooq/impl/Names.java   |  1 +
 .../main/java/org/jooq/impl/ParserImpl.java   |  6 +--
 4 files changed, 52 insertions(+), 15 deletions(-)

diff --git a/jOOQ/src/main/java/org/jooq/impl/DSL.java b/jOOQ/src/main/java/org/jooq/impl/DSL.java
index d64579fdb9..8e4bc7f81d 100644
--- a/jOOQ/src/main/java/org/jooq/impl/DSL.java
+++ b/jOOQ/src/main/java/org/jooq/impl/DSL.java
@@ -85,6 +85,8 @@ import static org.jooq.SQLDialect.SQLITE;
 // ...
 // ...
 // ...
+import static org.jooq.impl.Names.N_IF;
+import static org.jooq.impl.Names.N_IIF;
 import static org.jooq.impl.Names.N_SYSTEM_TIME;
 import static org.jooq.impl.PositionalWindowFunction.PositionalFunctionType.FIRST_VALUE;
 import static org.jooq.impl.PositionalWindowFunction.PositionalFunctionType.LAG;
@@ -12702,6 +12704,38 @@ public class DSL {
             return select.<T>asField();
     }
 
+    /**
+     * Create a MySQL style <code>IF(condition, ifTrue, ifFalse)</code> function.
+     */
+    @Support
+    public static <T> Field<T> if_(Condition condition, T ifTrue, T ifFalse) {
+        return iif0(N_IF, condition, Tools.field(ifTrue), Tools.field(ifFalse));
+    }
+
+    /**
+     * Create a MySQL style <code>IF(condition, ifTrue, ifFalse)</code> function.
+     */
+    @Support
+    public static <T> Field<T> if_(Condition condition, T ifTrue, Field<T> ifFalse) {
+        return iif0(N_IF, condition, Tools.field(ifTrue), nullSafe(ifFalse));
+    }
+
+    /**
+     * Create a MySQL style <code>IF(condition, ifTrue, ifFalse)</code> function.
+     */
+    @Support
+    public static <T> Field<T> if_(Condition condition, Field<T> ifTrue, T ifFalse) {
+        return iif0(N_IF, condition, nullSafe(ifTrue), Tools.field(ifFalse));
+    }
+
+    /**
+     * Create a MySQL style <code>IF(condition, ifTrue, ifFalse)</code> function.
+     */
+    @Support
+    public static <T> Field<T> if_(Condition condition, Field<T> ifTrue, Field<T> ifFalse) {
+        return iif0(N_IF, condition, nullSafe(ifTrue), nullSafe(ifFalse));
+    }
+
     /**
      * Initialise a {@link Case} statement.
      * <p>
@@ -13538,7 +13572,7 @@ public class DSL {
      */
     @Support
     public static <T> Field<T> iif(Condition condition, T ifTrue, T ifFalse) {
-        return iif0(condition, Tools.field(ifTrue), Tools.field(ifFalse));
+        return iif0(N_IIF, condition, Tools.field(ifTrue), Tools.field(ifFalse));
     }
 
     /**
@@ -13548,7 +13582,7 @@ public class DSL {
      */
     @Support
     public static <T> Field<T> iif(Condition condition, T ifTrue, Field<T> ifFalse) {
-        return iif0(condition, Tools.field(ifTrue, ifFalse), nullSafe(ifFalse));
+        return iif0(N_IIF, condition, Tools.field(ifTrue, ifFalse), nullSafe(ifFalse));
     }
 
     /**
@@ -13558,7 +13592,7 @@ public class DSL {
      */
     @Support
     public static <T> Field<T> iif(Condition condition, Field<T> ifTrue, T ifFalse) {
-        return iif0(condition, nullSafe(ifTrue), Tools.field(ifFalse, ifTrue));
+        return iif0(N_IIF, condition, nullSafe(ifTrue), Tools.field(ifFalse, ifTrue));
     }
 
     /**
@@ -13566,13 +13600,13 @@ public class DSL {
      */
     @Support
     public static <T> Field<T> iif(Condition condition, Field<T> ifTrue, Field<T> ifFalse) {
-        return iif0(condition, ifTrue, ifFalse);
+        return iif0(N_IIF, condition, ifTrue, ifFalse);
     }
 
     // Java 8 is stricter than Java 7 with respect to generics and overload
     // resolution (http://stackoverflow.com/q/5361513/521799)
-    static <T> Field<T> iif0(Condition condition, Field<T> ifTrue, Field<T> ifFalse) {
-        return new Iif<>(condition, nullSafe(ifTrue), nullSafe(ifFalse));
+    static <T> Field<T> iif0(Name name, Condition condition, Field<T> ifTrue, Field<T> ifFalse) {
+        return new Iif<>(name, condition, nullSafe(ifTrue), nullSafe(ifFalse));
     }
 
     // -------------------------------------------------------------------------
diff --git a/jOOQ/src/main/java/org/jooq/impl/Iif.java b/jOOQ/src/main/java/org/jooq/impl/Iif.java
index 138a41feb4..9714c62077 100644
--- a/jOOQ/src/main/java/org/jooq/impl/Iif.java
+++ b/jOOQ/src/main/java/org/jooq/impl/Iif.java
@@ -37,11 +37,10 @@
  */
 package org.jooq.impl;
 
-import static org.jooq.impl.Names.N_IIF;
-
 import org.jooq.Condition;
 import org.jooq.Context;
 import org.jooq.Field;
+import org.jooq.Name;
 
 /**
  * @author Lukas Eder
@@ -57,15 +56,14 @@ final class Iif<T> extends AbstractField<T> {
     private final Field<T>    ifTrue;
     private final Field<T>    ifFalse;
 
-    Iif(Condition condition, Field<T> ifTrue, Field<T> ifFalse) {
-        super(N_IIF, ifTrue.getDataType());
+    Iif(Name name, Condition condition, Field<T> ifTrue, Field<T> ifFalse) {
+        super(name, ifTrue.getDataType());
 
         this.condition = condition;
         this.ifTrue = ifTrue;
         this.ifFalse = ifFalse;
     }
 
-
     @Override
     public final void accept(Context<?> ctx) {
         switch (ctx.family()) {
@@ -75,9 +73,13 @@ final class Iif<T> extends AbstractField<T> {
 
 
 
+            case MARIADB:
+            case MYSQL:
+                ctx.visit(getUnqualifiedName()).sql('(').visit(condition).sql(", ").visit(ifTrue).sql(", ").visit(ifFalse).sql(')');
+                break;
 
             default:
-                ctx.visit(DSL.choose().when(condition, ifTrue).otherwise(ifFalse));
+                ctx.visit(DSL.when(condition, ifTrue).otherwise(ifFalse));
                 break;
         }
     }
diff --git a/jOOQ/src/main/java/org/jooq/impl/Names.java b/jOOQ/src/main/java/org/jooq/impl/Names.java
index 31a80794f9..6d03a3286d 100644
--- a/jOOQ/src/main/java/org/jooq/impl/Names.java
+++ b/jOOQ/src/main/java/org/jooq/impl/Names.java
@@ -110,6 +110,7 @@ final class Names {
     static final Name N_GROUP_CONCAT           = unquotedName("group_concat");
     static final Name N_HASHBYTES              = unquotedName("hashbytes");
     static final Name N_HEX                    = unquotedName("hex");
+    static final Name N_IF                     = unquotedName("if");
     static final Name N_IFNULL                 = unquotedName("ifnull");
     static final Name N_IIF                    = unquotedName("iif");
     static final Name N_INSTR                  = unquotedName("instr");
diff --git a/jOOQ/src/main/java/org/jooq/impl/ParserImpl.java b/jOOQ/src/main/java/org/jooq/impl/ParserImpl.java
index 979689bd80..997f7f47f6 100644
--- a/jOOQ/src/main/java/org/jooq/impl/ParserImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/ParserImpl.java
@@ -6330,7 +6330,7 @@ final class ParserImpl implements Parser {
                     return field;
                 else if ((field = parseFieldIsnullIf(ctx)) != null)
                     return field;
-                else if ((field = parseFieldIifIf(ctx)) != null)
+                else if ((field = parseFieldIfIf(ctx)) != null)
                     return field;
                 else
                     break;
@@ -9008,8 +9008,8 @@ final class ParserImpl implements Parser {
         return null;
     }
 
-    private static final Field<?> parseFieldIifIf(ParserContext ctx) {
-        if (parseFunctionNameIf(ctx, "IIF")) {
+    private static final Field<?> parseFieldIfIf(ParserContext ctx) {
+        if (parseFunctionNameIf(ctx, "IF") || parseFunctionNameIf(ctx, "IIF")) {
             parse(ctx, '(');
             Condition c = parseCondition(ctx);
             parse(ctx, ',');