Fixed errors in parser

Author: alex268

jdbc/src/main/java/tech/ydb/jdbc/query/YdbQueryParser.java

@@ -57,11 +57,7 @@ public QueryType detectQueryType() throws SQLException {
 
     @SuppressWarnings("MethodLength")
     public String parseSQL(String origin) throws SQLException {
-        this.statements.clear();
-        this.batcher.clear();
-
         int fragmentStart = 0;
-
         boolean detectJdbcArgs = false;
 
         QueryStatement currStatement = null;
@@ -78,6 +74,7 @@ public String parseSQL(String origin) throws SQLException {
         for (int i = 0; i < chars.length; ++i) {
             char ch = chars[i];
             boolean isInsideKeyword = false;
+            int keywordEnd = i; // parseSingleQuotes, parseDoubleQuotes, etc move index so we keep old value
             switch (ch) {
                 case '\'': // single-quotes
                     int singleQuitesEnd = parseSingleQuotes(chars, i);
@@ -140,7 +137,7 @@ public String parseSQL(String origin) throws SQLException {
 
             if (keywordStart >= 0 && (!isInsideKeyword || (i == chars.length - 1))) {
                 lastKeywordIsOffsetLimit = false;
-                int keywordLength = isInsideKeyword ? i - keywordStart - 1 : i - keywordStart;
+                int keywordLength = (isInsideKeyword ? i + 1 : keywordEnd) - keywordStart;
 
                 if (currStatement != null) {
                     batcher.readIdentifier(chars, keywordStart, keywordLength);
@@ -192,14 +189,14 @@ public String parseSQL(String origin) throws SQLException {
                             currStatement = new QueryStatement(QueryType.SCAN_QUERY, QueryCmd.SELECT);
                             // Skip SCAN prefix
                             parsed.append(chars, fragmentStart, keywordStart - fragmentStart);
-                            fragmentStart = isInsideKeyword ? i + 1 : i;
+                            fragmentStart = isInsideKeyword ? keywordEnd + 1 : keywordEnd;
                         }
                         // Detect explain expression - starts with EXPLAIN
                         if (parseExplainKeyword(chars, keywordStart)) {
                             currStatement = new QueryStatement(QueryType.EXPLAIN_QUERY, QueryCmd.SELECT);
                             // Skip EXPLAIN prefix
                             parsed.append(chars, fragmentStart, keywordStart - fragmentStart);
-                            fragmentStart = isInsideKeyword ? i + 1 : i;
+                            fragmentStart = isInsideKeyword ? keywordEnd + 1 : keywordEnd;
                         }
                     }
 
@@ -334,21 +331,16 @@ private static int parseBlockComment(final char[] query, int offset) {
         return offset;
     }
 
-    private static boolean isSpace(char c) {
-        return c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f';
-    }
-
     private static boolean parseAlterKeyword(char[] query, int offset) {
-        if (query.length < (offset + 6)) {
+        if (query.length < (offset + 5)) {
             return false;
         }
 
         return (query[offset] | 32) == 'a'
                 && (query[offset + 1] | 32) == 'l'
                 && (query[offset + 2] | 32) == 't'
                 && (query[offset + 3] | 32) == 'e'
-                && (query[offset + 4] | 32) == 'r'
-                && isSpace(query[offset + 5]);
+                && (query[offset + 4] | 32) == 'r';
     }
 
     private static boolean parseCreateKeyword(char[] query, int offset) {

jdbc/src/main/java/tech/ydb/jdbc/query/YqlBatcher.java

@@ -60,14 +60,6 @@ public boolean isValidBatch() {
                 && !columns.isEmpty() && columns.size() == values.size();
     }
 
-    public void clear() {
-        this.state = State.INIT;
-        this.cmd = null;
-        this.tableName = null;
-        this.columns.clear();
-        this.values.clear();
-    }
-
     public void readInsert() {
         if (state == State.INIT) {
             state = State.CMD;

jdbc/src/test/java/tech/ydb/jdbc/query/YdbQueryParserTest.java

@@ -24,6 +24,7 @@ public class YdbQueryParserTest {
         "'exPlain\nupsert to', '\nupsert to'",
         "'  Explain select * from table', '   select * from table'",
         "'\texPlain\nupsert to', '\t\nupsert to'",
+        "'EXPLAIN/*comment*/UPSERT INTO', '/*comment*/UPSERT INTO'",
         "'EXPLAIN',''",
     })
     public void explainQueryTest(String sql, String prepared) throws SQLException {
@@ -40,6 +41,7 @@ public void explainQueryTest(String sql, String prepared) throws SQLException {
     @ParameterizedTest(name = "[{index}] {0} is scheme query")
     @ValueSource(strings = {
         "  Alter table set;",
+        "Alter--comment\ntable set;",
         "drOp table 'test'",
         "-- comment \nCreate;",
     })
@@ -168,7 +170,7 @@ public void validBatchedInsertTest(String sql) throws SQLException {
         "Upsert into table_name(c1, c2, c3) values (?, ? , ?)",
         "\n  upsert into `table_name`  (\t`c1`, c2, c3)values(?, ? , ?)",
         "/* comment */ Upsert into `table_name`  (`c1`, /* commect */ c2, c3)values(?, ? , ?);\n-- post comment",
-        ";;Upsert into table_name (`c1`, /* comment */ c2, c3 )   values(?, ? , ?);",
+        ";;Upsert/* comment */into table_name (`c1`, /* comment */ c2, c3 )   values(?, ? , ?);",
     })
     public void validBatchedUpsertTest(String sql) throws SQLException {
         YdbQueryParser parser = new YdbQueryParser(true, true);