SQL: Return proper NUM_PREC_RADIX for non-numeric types (elastic/x-pack-elasticsearch#3086)

NUM_PREC_RADIX should be 10 for integer types, 2 for rational types and null for everything else.

relates elastic/x-pack-elasticsearch#3085

Original commit: elastic/x-pack-elasticsearch@81d5ee04b3

qa/sql/src/main/java/org/elasticsearch/xpack/qa/sql/jdbc/DatabaseMetaDataTestCase.java

@@ -76,6 +76,7 @@ public class DatabaseMetaDataTestCase extends JdbcIntegrationTestCase {
         index("test2", body -> {
             body.field("number", 7);
             body.field("date", "2017-01-01T01:01:01Z");
+            body.field("float", 42.0);
         });
 
         try (Connection h2 = LocalH2.anonymousDb();

qa/sql/src/main/resources/setup_mock_metadata_get_columns.sql

@@ -23,21 +23,23 @@ CREATE TABLE mock (
   IS_AUTOINCREMENT VARCHAR,
   IS_GENERATEDCOLUMN VARCHAR
 ) AS
-SELECT '', 'test1', 'name', 12, 'VARCHAR', 2147483647, null, null,
+SELECT '', 'test1', 'name', 12, 'VARCHAR', 2147483647, null, null, null,
-  10, -- TODO 10 seem wrong to hard code for non-numbers see https://github.com/elastic/x-pack-elasticsearch/issues/3085
   1, -- columnNullable
   null, null, null, null, null, 1, 'YES', null, null, null, null, '', ''
 FROM DUAL
 UNION ALL
-SELECT '', 'test2', 'date', 93, 'TIMESTAMP', 19, null, null,
+SELECT '', 'test2', 'date', 93, 'TIMESTAMP', 19, null, null, null,
-  10,
   1, -- columnNullable
   null, null, null, null, null, 1, 'YES', null, null, null, null, '', ''
 FROM DUAL
 UNION ALL
-SELECT '', 'test2', 'number', -5, 'BIGINT', 19, null, null,
+SELECT '', 'test2', 'float', 7, 'REAL', 7, null, null, 2,
-  10,
   1, -- columnNullable
   null, null, null, null, null, 2, 'YES', null, null, null, null, '', ''
 FROM DUAL
+UNION ALL
+SELECT '', 'test2', 'number', -5, 'BIGINT', 19, null, null, 10,
+  1, -- columnNullable
+  null, null, null, null, null, 3, 'YES', null, null, null, null, '', ''
+FROM DUAL
 ;

sql/jdbc/src/main/java/org/elasticsearch/xpack/sql/jdbc/jdbc/JdbcDatabaseMetaData.java

@@ -22,6 +22,8 @@ import java.sql.SQLFeatureNotSupportedException;
 import java.util.ArrayList;
 import java.util.List;
 
+import static org.elasticsearch.xpack.sql.jdbc.jdbc.JdbcUtils.numericPrecisionRadix;
+
 /**
  * Implementation of {@link DatabaseMetaData} for Elasticsearch. Draws inspiration
  * from <a href="https://www.postgresql.org/docs/9.0/static/information-schema.html">
@@ -822,7 +824,7 @@ class JdbcDatabaseMetaData implements DatabaseMetaData, JdbcWrapper {
             row[ 6] = col.size;
             row[ 7] = null;
             row[ 8] = null;
-            row[ 9] = 10;
+            row[ 9] = numericPrecisionRadix(col.type.getVendorTypeNumber());
             row[10] = columnNullable;
             row[11] = null;
             row[12] = null;

sql/jdbc/src/main/java/org/elasticsearch/xpack/sql/jdbc/jdbc/JdbcUtils.java

@@ -198,4 +198,22 @@ public abstract class JdbcUtils {
     static JDBCType type(int jdbcType) {
         return JDBCType.valueOf(jdbcType);
     }
+
+    static Integer numericPrecisionRadix(int type) {
+        switch (type) {
+            case TINYINT:
+            case SMALLINT:
+            case INTEGER:
+            case BIGINT:
+                return 10;
+            case REAL:
+            case DOUBLE:
+            case FLOAT:
+            case DECIMAL:
+            case NUMERIC:
+                return 2;
+            default:
+                return null;
+        }
+    }
 }