fix: #464 JSON_VALUE RETURNING

Author: liuxy0551

src/grammar/flink/FlinkSqlLexer.g4

@@ -306,6 +306,7 @@ KW_PERCENTILE_DISC     : 'PERCENTILE_DISC';
 KW_PERCENT_RANK        : 'PERCENT_RANK';
 KW_PERIOD              : 'PERIOD';
 KW_PERMUTE             : 'PERMUTE';
+KW_RETURNING           : 'RETURNING';
 KW_PIVOT               : 'PIVOT';
 KW_PORTION             : 'PORTION';
 KW_POSITION            : 'POSITION';

src/grammar/flink/FlinkSqlParser.g4

@@ -794,6 +794,7 @@ primaryExpression
     | dereferenceDefinition                                                            # dereference
     | LR_BRACKET expression RR_BRACKET                                                 # parenthesizedExpression
     | KW_EXTRACT LR_BRACKET field=identifier KW_FROM source=valueExpression RR_BRACKET # extract
+    | jsonValueExpression                                                              # jsonValue
     // | (SUBSTR | SUBSTRING) LR_BRACKET str=valueExpression (KW_FROM | COMMA) pos=valueExpression
     //   ((KW_FOR | COMMA) len=valueExpression)? RR_BRACKET                                                   #substring
     // | TRIM LR_BRACKET trimOption=(BOTH | LEADING | TRAILING)? (trimStr=valueExpression)?
@@ -802,6 +803,10 @@ primaryExpression
     //   KW_FROM position=valueExpression (KW_FOR length=valueExpression)? RR_BRACKET                          #overlay
     ;
 
+jsonValueExpression
+    : KW_JSON_VALUE LR_BRACKET expression COMMA stringLiteral (KW_RETURNING columnType)? RR_BRACKET
+    ;
+
 functionNameCreate
     : uid
     ;