[feat] Added EXISTS keyword

Author: ANeumann82

src/main/java/module-info.java

@@ -58,6 +58,4 @@
     exports net.sf.jsqlparser.util.validation.feature;
     exports net.sf.jsqlparser.util.validation.metadata;
     exports net.sf.jsqlparser.util.validation.validator;
-    exports net.sf.jsqlparser.expression.json;
-    exports net.sf.jsqlparser.statement.from;
 }

src/main/java/net/sf/jsqlparser/expression/JsonTableFunction.java

@@ -33,11 +33,11 @@ public String getDisplay() {
     }
 
     public enum JsonTableOnErrorType {
-        ERROR, NULL, EMPTY
+        ERROR, NULL, EMPTY, TRUE, FALSE
     }
 
     public enum JsonTableOnEmptyType {
-        ERROR, NULL, EMPTY
+        ERROR, NULL, EMPTY, TRUE, FALSE
     }
 
     public enum JsonTableParsingType {
@@ -466,6 +466,8 @@ public static class JsonTableValueColumnDefinition extends JsonTableColumnDefini
         private boolean forOrdinality;
         private ColDataType dataType;
         private boolean formatJson;
+        private boolean exists;
+        private boolean onEmptyAfterOnError;
         private String encoding;
         private Expression pathExpression;
         private JsonTableWrapperClause wrapperClause;
@@ -483,6 +485,17 @@ public JsonTableValueColumnDefinition setColumnName(String columnName) {
             return this;
         }
 
+
+        public JsonTableValueColumnDefinition setExistsKeyword(boolean exists) {
+            this.exists = exists;
+            return this;
+        }
+
+        public JsonTableValueColumnDefinition setOnEmptyAfterOnError(boolean b) {
+            this.onEmptyAfterOnError = b;
+            return this;
+        }
+
         public boolean isForOrdinality() {
             return forOrdinality;
         }
@@ -595,6 +608,9 @@ public String toString() {
                 builder.append(" FOR ORDINALITY");
                 return builder.toString();
             }
+            if (exists) {
+                builder.append(" EXISTS");
+            }
             if (dataType != null) {
                 builder.append(" ").append(dataType);
             }
@@ -621,12 +637,15 @@ public String toString() {
             if (quotesClause != null) {
                 builder.append(" ").append(quotesClause);
             }
-            if (onEmptyBehavior != null) {
+            if (onEmptyBehavior != null && !onEmptyAfterOnError) {
                 builder.append(" ").append(onEmptyBehavior).append(" ON EMPTY");
             }
             if (onErrorBehavior != null) {
                 builder.append(" ").append(onErrorBehavior).append(" ON ERROR");
             }
+            if (onEmptyBehavior != null && onEmptyAfterOnError) {
+                builder.append(" ").append(onEmptyBehavior).append(" ON EMPTY");
+            }
             return builder.toString();
         }
     }