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https://issues.apache.org/jira/browse/CALCITE-2282?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16818921#comment-16818921
]
Lai Zhou commented on CALCITE-2282:
-----------------------------------
+1.[~julianhyde] , is there a good way to solve this ?
I use a customized parser to override the createCall method of
SqlAbstractParserImpl to activate my OperatorTable.
I think it's a typical case that respond to the Calcite's objective: One
planner fits all.
{code:java}
public class ${parser.class} extends SqlAbstractParserImpl
{
private static final Logger LOGGER = CalciteTrace.getParserTracer();
// Can't use quoted literal because of a bug in how JavaCC translates
// backslash-backslash.
private static final char BACKSLASH = 0x5c;
private static final char DOUBLE_QUOTE = 0x22;
private static final String DQ = DOUBLE_QUOTE + "";
private static final String DQDQ = DQ + DQ;
private static Metadata metadata;
private Casing unquotedCasing;
private Casing quotedCasing;
private int identifierMaxLength;
private SqlConformance conformance;
/**
* {@link SqlParserImplFactory} implementation for creating parser.
*/
public static final SqlParserImplFactory FACTORY = new
SqlParserImplFactory() {
public SqlAbstractParserImpl getParser(Reader stream) {
return new ${parser.class}(stream);
}
};
@Override
public SqlCall createCall(
SqlIdentifier funName,
SqlParserPos pos,
SqlFunctionCategory funcType,
SqlLiteral functionQualifier,
SqlNode[] operands) {
SqlOperator fun = null;
// First, try a half-hearted resolution as a builtin function.
// If we find one, use it; this will guarantee that we
// preserve the correct syntax (i.e. don't quote builtin function
/// name when regenerating SQL).
if (funName.isSimple()) {
final List list = new ArrayList();
HiveSqlOperatorTable.instance().lookupOperatorOverloads(funName,
funcType, SqlSyntax.FUNCTION, list);
if (list.size() > 0) {
fun = (SqlOperator) list.get(0);
}
}
// Otherwise, just create a placeholder function. Later, during
// validation, it will be resolved into a real function reference.
if (fun == null) {
fun = new SqlUnresolvedFunction(funName, null, null, null, null,
funcType);
}
return fun.createCall(functionQualifier, pos, operands);
}
{code}
> Allow OperatorTable to be pluggable in the parser
> -------------------------------------------------
>
> Key: CALCITE-2282
> URL: https://issues.apache.org/jira/browse/CALCITE-2282
> Project: Calcite
> Issue Type: Bug
> Components: core
> Reporter: Sudheesh Katkam
> Priority: Major
> Attachments: CALCITE-2282.patch.txt
>
>
> SqlAbstractParserImpl [hardcodes OperatorTable to
> SqlStdOperatorTable|https://github.com/apache/calcite/blob/8327e674e7f0a768d124fa37fd75cda4b8a35bb6/core/src/main/java/org/apache/calcite/sql/parser/SqlAbstractParserImpl.java#L334|https://github.com/apache/calcite/blob/8327e674e7f0a768d124fa37fd75cda4b8a35bb6/core/src/main/java/org/apache/calcite/sql/parser/SqlAbstractParserImpl.java#L334].
> Make this pluggable via a protected method.
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