/**
* The name of a given column
* @see java.sql.ResultSetMetaData#getColumnName
* @param column the column whose name is wanted
* @return the name of the requested column
*/
public String getColumnName(int column)
{// throws SQLException {
// get the column and return its name
//
String columnName;
int dotAt;
TsColumn col = tsql.columnAtIndex(column - 1);
dotAt = col.name.indexOf(".");
columnName = col.name;
if (dotAt > -1)
{
columnName = col.name.substring(dotAt + 1);
}
if (col.alias != (String)null)
{
if (!col.alias.equals(columnName))
{
return(col.alias);
}
}
columnName = TinySQLGlobals.getLongName(columnName);
return(columnName);
}
/**
* Gets a description of table columns available in
* the specified catalog.
*
* <P>Only column descriptions matching the catalog, schema, table
* and column name criteria are returned. They are ordered by
* TABLE_SCHEM, TABLE_NAME and ORDINAL_POSITION.
*
* <P>Each column description has the following columns:
* <OL>
* <LI><B>TABLE_CAT</B> String => table catalog (may be null)
* <LI><B>TABLE_SCHEM</B> String => table schema (may be null)sRow record = new TsRow();
*
* <LI><B>TABLE_NAME</B> String => table name
* <LI><B>COLUMN_NAME</B> String => column name
* <LI><B>DATA_TYPE</B> short => SQL type from java.sql.Types
* <LI><B>TYPE_NAME</B> String => Data source dependent type name,
* for a UDT the type name is fully qualified
* <LI><B>COLUMN_SIZE</B> int => column size. For char or date
* types this is the maximum number of characters, for numeric or
* decimal types this is precision.
* <LI><B>BUFFER_LENGTH</B> is not used.
* <LI><B>DECIMAL_DIGITS</B> int => the number of fractional digits
* <LI><B>NUM_PREC_RADIX</B> int => Radix (typically either 10 or 2)
* <LI><B>NULLABLE</B> int => is NULL allowed?
* <UL>
* <LI> columnNoNulls - might not allow NULL values
* <LI> columnNullable - definitely allows NULL values
* <LI> columnNullableUnknown - nullability unknown
* </UL>
* <LI><B>REMARKS</B> String => comment describing column (may be null)
* <LI><B>COLUMN_DEF</B> String => default value (may be null)
* <LI><B>SQL_DATA_TYPE</B> int => unused
* <LI><B>SQL_DATETIME_SUB</B> int => unused
* <LI><B>CHAR_OCTET_LENGTH</B> int => for char types the
* maximum number of bytes in the column
* <LI><B>ORDINAL_POSITION</B> int => index of column in table
* (starting at 1)
* <LI><B>IS_NULLABLE</B> String => "NO" means column definitely
* does not allow NULL values; "YES" means the column might
* allow NULL values. An empty string means nobody knows.
* </OL>
*
* @param catalog a catalog name; "" retrieves those without a
* catalog; null means drop catalog name from the selection criteria
* @param schemaPattern a schema name pattern; "" retrieves those
* without a schema
* @param tableNamePattern a table name pattern
* @param columnNamePattern a column name pattern
* @return ResultSet - each row is a column description
* @exception SQLException if a database access error occurs
* @see #getSearchStringEscape
*/
public override java.sql.ResultSet getColumns(String catalog, String schemaPattern,
String tableNamePattern, String columnNamePattern)
{
int i;
String columnNameKey;
try
{
String dataDir = getDataDir();
Utils.log("Entering getColumns(tableNamePattern='" + tableNamePattern + "')");
if (dataDir == null)
{
return(null);
}
java.sql.ResultSet tableRs = getTables(catalog, schemaPattern, tableNamePattern, null);
TsResultSet jrs = new TsResultSet();
TsColumn jsc = new TsColumn("TABLE_CAT");
jsc.type = java.sql.Types.CHAR;
jsc.size = 9;
jrs.addColumn(jsc);
jsc = new TsColumn("TABLE_SCHEM");
jsc.type = java.sql.Types.CHAR;
jsc.size = 11;
jrs.addColumn(jsc);
jsc = new TsColumn("TABLE_NAME");
jsc.type = java.sql.Types.CHAR;
jsc.size = 10;
jrs.addColumn(jsc);
jsc = new TsColumn("COLUMN_NAME");
jsc.type = java.sql.Types.CHAR;
jsc.size = 11;
jrs.addColumn(jsc);
jsc = new TsColumn("DATA_TYPE");
jsc.type = java.sql.Types.INTEGER;
jsc.size = 6;
jrs.addColumn(jsc);
jsc = new TsColumn("TYPE_NAME");
jsc.type = java.sql.Types.CHAR;
jsc.size = 9;
jrs.addColumn(jsc);
jsc = new TsColumn("COLUMN_SIZE");
jsc.type = java.sql.Types.INTEGER;
jsc.size = 8;
jrs.addColumn(jsc);
jsc = new TsColumn("BUFFER_LENGTH");
jsc.type = java.sql.Types.INTEGER;
jsc.size = 8;
jrs.addColumn(jsc);
jsc = new TsColumn("DECIMAL_DIGITS");
jsc.type = java.sql.Types.INTEGER;
jsc.size = 8;
jrs.addColumn(jsc);
jsc = new TsColumn("NUM_PREC_RADIX");
jsc.type = java.sql.Types.INTEGER;
jsc.size = 8;
jrs.addColumn(jsc);
jsc = new TsColumn("NULLABLE");
jsc.type = java.sql.Types.INTEGER;
jsc.size = 8;
jrs.addColumn(jsc);
jsc = new TsColumn("REMARKS");
jsc.type = java.sql.Types.CHAR;
jsc.size = 128;
jrs.addColumn(jsc);
jsc = new TsColumn("COLUMN_DEF");
jsc.type = java.sql.Types.CHAR;
jsc.size = 128;
jrs.addColumn(jsc);
jsc = new TsColumn("SQL_DATA_TYPE");
jsc.type = java.sql.Types.INTEGER;
jsc.size = 128;
jrs.addColumn(jsc);
// Several parameters missing.
jsc = new TsColumn("IS_NULLABLE");
jsc.type = java.sql.Types.CHAR;
jsc.size = 3;
jrs.addColumn(jsc);
while (tableRs.next())
{ // process each DBF file and extract column info ...
String tableName = tableRs.getString("TABLE_NAME");
DBFFileTable tbl;
try
{
tbl = new DBFFileTable(dataDir, tableName);
}
catch (Exception)
{
continue; // ignore buggy and empty (zero byte size) DBF files
}
Utils.log("Accessing column info for table " + tableName);
java.util.Hashtable <Object, Object> column_info = tbl.column_info;
for (i = 0; i < tbl.columnNameKeys.size(); i++)
{
columnNameKey = (String)tbl.columnNameKeys.elementAt(i);
TsColumn tsc = (TsColumn)column_info.get(columnNameKey);
// process each column of the current table ...
TsRow record = new TsRow();
record.put("TABLE_CAT", "");
record.put("TABLE_SCHEM", "");
record.put("TABLE_NAME", tableName);
record.put("COLUMN_NAME", TinySQLGlobals.getLongName(tsc.name));
record.put("DATA_TYPE", new java.lang.Integer(tsc.type).toString());
record.put("TYPE_NAME", DBFFile.typeToLiteral(tsc.type).toString());
record.put("COLUMN_SIZE", new java.lang.Integer(tsc.size).toString());
record.put("DECIMAL_DIGITS", new java.lang.Integer(tsc.decimalPlaces).toString());
int nullable = columnNoNulls;
if (tsc.notNull == true)
{
nullable = columnNullable;
}
record.put("NULLABLE", new java.lang.Integer(nullable).toString());
record.put("REMARKS", "noRemarks");
String defaultVal = tsc.defaultVal;
if (defaultVal == null)
{
defaultVal = "";
}
record.put("COLUMN_DEF", defaultVal);
String isNullable = "NO";
if (tsc.notNull == true)
{
isNullable = "YES";
}
record.put("IS_NULLABLE", isNullable);
/*
* Suppress any sorting of the ResultSet. Column Metadata should
* be presented in the order the columns exist in the dBase header.
*/
jrs.addRow(record, false);
}
tbl.close();
tbl = null;
}
return(new TinySQLResultSet(jrs, (TinySQLStatement)null));
}
catch (Exception)
{
return(null);
}
}