Change CI_DB_driver::field_data() signature

The parameter is mandatory, it doesn't make sense to have a default
empty string value only to check for it.
diff --git a/system/database/drivers/cubrid/cubrid_driver.php b/system/database/drivers/cubrid/cubrid_driver.php
index 3e36ecc..438b48a 100644
--- a/system/database/drivers/cubrid/cubrid_driver.php
+++ b/system/database/drivers/cubrid/cubrid_driver.php
@@ -347,13 +347,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		if (($query = $this->query('SHOW COLUMNS FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE))) === FALSE)
 		{
 			return FALSE;
diff --git a/system/database/drivers/ibase/ibase_driver.php b/system/database/drivers/ibase/ibase_driver.php
index aac6068..20c5d9c 100644
--- a/system/database/drivers/ibase/ibase_driver.php
+++ b/system/database/drivers/ibase/ibase_driver.php
@@ -264,13 +264,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		$sql = 'SELECT "rfields"."RDB$FIELD_NAME" AS "name",
 				CASE "fields"."RDB$FIELD_TYPE"
 					WHEN 7 THEN \'SMALLINT\'
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 2fd21db..1aeff1d 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -344,13 +344,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		$sql = 'SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, NUMERIC_PRECISION, COLUMN_DEFAULT
 			FROM INFORMATION_SCHEMA.Columns
 			WHERE UPPER(TABLE_NAME) = '.$this->escape(strtoupper($table));
diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index 819d5e5..41cb14b 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -419,13 +419,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		if (($query = $this->query('SHOW COLUMNS FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE))) === FALSE)
 		{
 			return FALSE;
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index 4f58e83..4370986 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -402,13 +402,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		if (($query = $this->query('SHOW COLUMNS FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE))) === FALSE)
 		{
 			return FALSE;
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index 162a87b..f57e042 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -535,13 +535,9 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-		elseif (strpos($table, '.') !== FALSE)
+		if (strpos($table, '.') !== FALSE)
 		{
 			sscanf($table, '%[^.].%s', $owner, $table);
 		}
diff --git a/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php b/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
index f8e60f9..9ed6631 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
@@ -142,13 +142,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		if (($query = $this->query('SHOW COLUMNS FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE))) === FALSE)
 		{
 			return FALSE;
diff --git a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
index 1116238..d1d4287 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
@@ -192,13 +192,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		$sql = 'SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, NUMERIC_PRECISION, COLUMN_DEFAULT
 			FROM INFORMATION_SCHEMA.Columns
 			WHERE UPPER(TABLE_NAME) = '.$this->escape(strtoupper($table));
diff --git a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
index 2ada478..5fffd5a 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
@@ -150,13 +150,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		$sql = 'SELECT "rfields"."RDB$FIELD_NAME" AS "name",
 				CASE "fields"."RDB$FIELD_TYPE"
 					WHEN 7 THEN \'SMALLINT\'
diff --git a/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php b/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
index b639df1..17a7732 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_ibm_driver.php
@@ -174,7 +174,7 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
 		$sql = 'SELECT "colname" AS "name", "typename" AS "type", "default" AS "default", "length" AS "max_length",
 				CASE "keyseq" WHEN NULL THEN 0 ELSE 1 END AS "primary_key"
diff --git a/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php b/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
index a293e3d..01e32f5 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
@@ -187,7 +187,7 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
 		$sql = 'SELECT "syscolumns"."colname" AS "name",
 				CASE "syscolumns"."coltype"
diff --git a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
index fe75af7..e4e4fa0 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
@@ -199,13 +199,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		if (($query = $this->query('SHOW COLUMNS FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE))) === FALSE)
 		{
 			return FALSE;
diff --git a/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php b/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
index 33c7c2a..b80da33 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
@@ -184,13 +184,9 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-		elseif (strpos($table, '.') !== FALSE)
+		if (strpos($table, '.') !== FALSE)
 		{
 			sscanf($table, '%[^.].%s', $owner, $table);
 		}
diff --git a/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
index 1707e1d..158c5d2 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
@@ -261,13 +261,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		$sql = 'SELECT "column_name", "data_type", "character_maximum_length", "numeric_precision", "column_default"
 			FROM "information_schema"."columns"
 			WHERE LOWER("table_name") = '.$this->escape(strtolower($table));
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php b/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
index e37db47..e1c8670 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlite_driver.php
@@ -142,13 +142,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		if (($query = $this->query('PRAGMA TABLE_INFO('.$this->protect_identifiers($table, TRUE, NULL, FALSE).')')) === FALSE)
 		{
 			return FALSE;
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
index f507837..ac35135 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
@@ -221,13 +221,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		$sql = 'SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, NUMERIC_PRECISION, COLUMN_DEFAULT
 			FROM INFORMATION_SCHEMA.Columns
 			WHERE UPPER(TABLE_NAME) = '.$this->escape(strtoupper($table));
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index c98c14e..fa59349 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -463,13 +463,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		$sql = 'SELECT "column_name", "data_type", "character_maximum_length", "numeric_precision", "column_default"
 			FROM "information_schema"."columns"
 			WHERE LOWER("table_name") = '.$this->escape(strtolower($table));
diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
index fe48e9b..2137bad 100644
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ b/system/database/drivers/sqlite/sqlite_driver.php
@@ -263,13 +263,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		if (($query = $this->query('PRAGMA TABLE_INFO('.$this->protect_identifiers($table, TRUE, NULL, FALSE).')')) === FALSE)
 		{
 			return FALSE;
diff --git a/system/database/drivers/sqlite3/sqlite3_driver.php b/system/database/drivers/sqlite3/sqlite3_driver.php
index a681574..27d2bbf 100644
--- a/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -268,13 +268,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		if (($query = $this->query('PRAGMA TABLE_INFO('.$this->protect_identifiers($table, TRUE, NULL, FALSE).')')) === FALSE)
 		{
 			return FALSE;
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index d774f6b..078aaec 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -355,13 +355,8 @@
 	 * @param	string	$table
 	 * @return	array
 	 */
-	public function field_data($table = '')
+	public function field_data($table)
 	{
-		if ($table === '')
-		{
-			return ($this->db_debug) ? $this->display_error('db_field_param_missing') : FALSE;
-		}
-
 		$sql = 'SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, NUMERIC_PRECISION, COLUMN_DEFAULT
 			FROM INFORMATION_SCHEMA.Columns
 			WHERE UPPER(TABLE_NAME) = '.$this->escape(strtoupper($table));