Flink DQL SQL With Calcite

DESCRIBE、EXPLAIN、SHOW 等 Statement 相关 SQL 解析。

Flink SQL 解析的代码参考：Flink SQL 解析

Parser.tdd 和 parserImpls.ftl 文件中的相关变更如下：

Parser.tdd

imports: [
    ...
    "com.matty.flink.sql.parser.dql.SqlShowTables",
    "com.matty.flink.sql.parser.dql.SqlRichExplain",
    "com.matty.flink.sql.parser.dql.SqlRichDescribeTable",
    "com.matty.flink.sql.parser.dml.SqlStatementSet",
    "java.util.Set"
    "java.util.HashSet"
    "com.matty.flink.sql.parser.utils.ParserResource"
]

keywords: [
    ...
    "EXTENDED",
    "ESTIMATED_COST",
    "CHANGELOG_MODE",
    "JSON_EXECUTION_PLAN",
    "TABLES"
]

statementParserMethods: [
    ...
    "SqlRichDescribeTable()"
    "SqlRichExplain()"
    "SqlShowTables()"
]

parserImpls.ftl

...
/**
 * DESCRIBE | DESC [ EXTENDED] [[catalogName.] dataBasesName].tableName sql call.
 * Here we add Rich in className to distinguish from calcite's original SqlDescribeTable.
 */
SqlRichDescribeTable SqlRichDescribeTable() :
{
    SqlIdentifier tableName;
    SqlParserPos pos;
    boolean isExtended = false;
}
{
    ( <DESCRIBE> | <DESC> ) { pos = getPos();}
    [ <EXTENDED> { isExtended = true;} ]
    tableName = CompoundIdentifier()
    {
        return new SqlRichDescribeTable(pos, tableName, isExtended);
    }
}

/**
* Parses an explain module statement.
*/
SqlNode SqlRichExplain() :
{
    SqlNode stmt;
    Set<String> explainDetails = new HashSet<String>();
}
{
    (
    LOOKAHEAD(3) <EXPLAIN> <PLAN> <FOR>
    |
    LOOKAHEAD(2) <EXPLAIN> ParseExplainDetail(explainDetails) ( <COMMA> ParseExplainDetail(explainDetails) )*
    |
    <EXPLAIN>
    )
    (
        stmt = SqlStatementSet()
        |
        stmt = OrderedQueryOrExpr(ExprContext.ACCEPT_QUERY)
        |
        stmt = RichSqlInsert()
    )
    {
        return new SqlRichExplain(getPos(), stmt, explainDetails);
    }
}

/**
* Parse a statement set.
*
* STATEMENT SET BEGIN (RichSqlInsert();)+ END
*/
SqlNode SqlStatementSet() :
{
    SqlParserPos startPos;
    SqlNode insert;
    List<RichSqlInsert> inserts = new ArrayList<RichSqlInsert>();
}
{
    <STATEMENT>{ startPos = getPos(); } <SET> <BEGIN>
    (
        insert = RichSqlInsert()
        <SEMICOLON>
        {
            inserts.add((RichSqlInsert) insert);
        }
    )+
    <END>
    {
        return new SqlStatementSet(inserts, startPos);
    }
}

void ParseExplainDetail(Set<String> explainDetails):
{
}
{
    (
        <ESTIMATED_COST>
        |
        <CHANGELOG_MODE>
        |
        <JSON_EXECUTION_PLAN>
    )
    {
        if (explainDetails.contains(token.image.toUpperCase())) {
            throw SqlUtil.newContextException(
                getPos(),
                ParserResource.RESOURCE.explainDetailIsDuplicate());
        } else {
            explainDetails.add(token.image.toUpperCase());
        }
    }
}

/**
* SHOW TABLES FROM [catalog.] database sql call.
*/
SqlShowTables SqlShowTables() :
{
    SqlIdentifier databaseName = null;
    SqlCharStringLiteral likeLiteral = null;
    String prep = null;
    boolean notLike = false;
    SqlParserPos pos;
}
{
    <SHOW> <TABLES>
    { pos = getPos(); }
    [
        ( <FROM> { prep = "FROM"; } | <IN> { prep = "IN"; } )
        { pos = getPos(); }
        databaseName = CompoundIdentifier()
    ]
    [
        [
            <NOT>
            {
                notLike = true;
            }
        ]
        <LIKE>  <QUOTED_STRING>
        {
            String likeCondition = SqlParserUtil.parseString(token.image);
            likeLiteral = SqlLiteral.createCharString(likeCondition, getPos());
        }
    ]
    {
        return new SqlShowTables(pos, prep, databaseName, notLike, likeLiteral);
    }
}

DESCRIBE

SqlRichDescribeTableTest.javagit 地址

public class SqlRichDescribeTableTest extends BaseParser {

    @Test
    public void describeTable() {
        String sql = "DESC Orders";

        final SqlNode sqlNode = parseStmtAndHandleEx(sql);
        assert sqlNode instanceof SqlRichDescribeTable;
        final SqlRichDescribeTable sqlRichDescribeTable = (SqlRichDescribeTable) sqlNode;

        // SqlRichDescribeTable -> DescribeTableOperation
        // catalogManager.getTable(ObjectIdentifier)
        String[] fullTableName = sqlRichDescribeTable.fullTableName();
        LOG.debug("fullTableName: {}", fullTableName);
    }
}

EXPLAIN

SqlRichExplainTest.java

public class SqlRichExplainTest extends BaseParser {

    @Test
    public void explainForCBO() {
        String sql = "EXPLAIN ESTIMATED_COST, CHANGELOG_MODE, JSON_EXECUTION_PLAN \n" +
                "  SELECT `count`, word FROM MyTable1 WHERE word LIKE 'F%' \n" +
                "  UNION ALL \n" +
                "  SELECT `count`, word FROM MyTable2";

        final SqlNode sqlNode = parseStmtAndHandleEx(sql);
        assert sqlNode instanceof SqlRichExplain;
        final SqlRichExplain sqlRichExplain = (SqlRichExplain) sqlNode;

        // ExplainOperation(PlannerQueryOperation)
        SqlNode sqlQueryNode = sqlRichExplain.getStatement();
        assert sqlQueryNode.getKind().belongsTo(SqlKind.QUERY);

        Set<String> explainDetails = sqlRichExplain.getExplainDetails();
        LOG.debug("explainDetails: {}", explainDetails);

        List<SqlNode> operandList = sqlRichExplain.getOperandList();
        LOG.debug("operandList: {}", operandList);
    }

}

SHOW

SqlShowTablesTest.java

public class SqlShowTablesTest extends BaseParser {
   
    @Test
    public void showTables() {
        String sql = "show tables";

        final SqlNode sqlNode = parseStmtAndHandleEx(sql);
        assert sqlNode instanceof SqlShowTables;
        final SqlShowTables sqlShowTables = (SqlShowTables) sqlNode;

        // SqlShowTables -> ShowTablesOperation -> catalogManager.listTables
        List<SqlNode> operandList = sqlShowTables.getOperandList();

        LOG.debug("operandList: {}", operandList);
    }

}