feat: functions with extra keywords, like BigQuery Timeseries functions

- fixes #2120

Signed-off-by: Andreas Reichel <[email protected]>
Signed-off-by: manticore-projects <[email protected]>

Author: manticore-projects

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

@@ -39,6 +39,7 @@ public class Function extends ASTNodeAccessImpl implements Expression {
     private Limit limit = null;
     private KeepExpression keep = null;
     private String onOverflowTruncate = null;
+    private String extraKeyword = null;
 
     public Function() {}
 
@@ -255,6 +256,15 @@ public void setKeep(KeepExpression keep) {
         this.keep = keep;
     }
 
+    public String getExtraKeyword() {
+        return extraKeyword;
+    }
+
+    public Function setExtraKeyword(String extraKeyword) {
+        this.extraKeyword = extraKeyword;
+        return this;
+    }
+
     @Override
     @SuppressWarnings({"PMD.CyclomaticComplexity", "PMD.NPathComplexity"})
     public String toString() {
@@ -272,6 +282,11 @@ public String toString() {
                 if (isAllColumns()) {
                     b.append("ALL ");
                 }
+
+                if (extraKeyword != null) {
+                    b.append(extraKeyword).append(" ");
+                }
+
                 b.append(parameters);
 
                 if (havingClause != null) {

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -5903,6 +5903,7 @@ Function InternalFunction(boolean escaped):
     String onOverflowTruncate = null;
     Token overflowToken = null;
     Limit limit;
+    Token extraKeywordToken;
 }
 {
     [ LOOKAHEAD(2) prefixToken = <K_APPROXIMATE> ]
@@ -5922,7 +5923,8 @@ Function InternalFunction(boolean escaped):
             |
             LOOKAHEAD( AllTableColumns() ) expr=AllTableColumns() { expressionList = new ExpressionList(expr); }
             |
-            LOOKAHEAD(3) expressionList=ExpressionList()
+            LOOKAHEAD(3) [ LOOKAHEAD(2) extraKeywordToken = <K_TABLE> { retval.setExtraKeyword(extraKeywordToken.image); } ]
+            expressionList=ExpressionList()
             [ orderByList = OrderByElements() { retval.setOrderByElements(orderByList); } ]
 
             // https://docs.oracle.com/en/database/oracle/oracle-database/21/sqlrf/LISTAGG.html

src/test/java/net/sf/jsqlparser/statement/select/BigQueryTest.java

@@ -11,6 +11,7 @@
 
 import net.sf.jsqlparser.JSQLParserException;
 import net.sf.jsqlparser.test.TestUtils;
+import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
@@ -92,4 +93,21 @@ void testAsValue() throws JSQLParserException {
         String sqlStr = "SELECT AS VALUE STRUCT(1 AS a, 2 AS b) xyz";
         TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
     }
+
+    @Test
+    void testTimeSeriesFunction() throws JSQLParserException {
+        String sqlStr = "with raw_data as (\n"
+                + "    select timestamp('2024-12-01') zetime\n"
+                + "    union all \n"
+                + "    select timestamp('2024-12-04')\n"
+                + "  )\n"
+                + "select zetime from GAP_FILL(\n"
+                + "  TABLE raw_data,\n"
+                + "  ts_column => 'zetime',\n"
+                + "  bucket_width => INTERVAL 4 HOUR\n"
+                + ")";
+        PlainSelect select = (PlainSelect) TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
+        TableFunction function = select.getFromItem(TableFunction.class);
+        Assertions.assertEquals("TABLE", function.getFunction().getExtraKeyword());
+    }
 }