diff --git a/wp-admin/admin-db.php b/wp-admin/admin-db.php
index dd6031ecb1..314892a225 100644
--- a/wp-admin/admin-db.php
+++ b/wp-admin/admin-db.php
@@ -245,7 +245,7 @@ function category_exists($cat_name) {
 	if (!$category_nicename = sanitize_title($cat_name))
 		return 0;
 
-	return $wpdb->get_var("SELECT cat_ID FROM $wpdb->categories WHERE category_nicename = '$category_nicename'");
+	return (int) $wpdb->get_var("SELECT cat_ID FROM $wpdb->categories WHERE category_nicename = '$category_nicename'");
 }
 
 function wp_delete_user($id, $reassign = 'novalue') {
@@ -299,6 +299,8 @@ function wp_insert_link($linkdata) {
 	if ( !empty($link_id) )
 		$update = true;
 
+	$link_id = (int) $link_id;
+
 	if( trim( $link_name ) == '' )
 		return 0;
 	$link_name = apply_filters('pre_link_name', $link_name);
@@ -443,7 +445,7 @@ function wp_set_link_cats($link_ID = 0, $link_categories = array()) {
 	$old_categories = $wpdb->get_col("
 		SELECT category_id
 		FROM $wpdb->link2cat
-		WHERE link_id = $link_ID");
+		WHERE link_id = '$link_ID'");
 
 	if (!$old_categories) {
 		$old_categories = array();
@@ -456,10 +458,11 @@ function wp_set_link_cats($link_ID = 0, $link_categories = array()) {
 
 	if ($delete_cats) {
 		foreach ($delete_cats as $del) {
+			$del = (int) $del;
 			$wpdb->query("
 				DELETE FROM $wpdb->link2cat
-				WHERE category_id = $del
-					AND link_id = $link_ID
+				WHERE category_id = '$del'
+					AND link_id = '$link_ID'
 				");
 		}
 	}
diff --git a/wp-includes/bookmark-template.php b/wp-includes/bookmark-template.php
index 45846f44cd..e7a84805d0 100644
--- a/wp-includes/bookmark-template.php
+++ b/wp-includes/bookmark-template.php
@@ -165,8 +165,7 @@ function get_linkcatname($id = 0) {
 	if ( empty($cats) || ! is_array($cats) )
 		return '';
 
-	$cat_id = (int) 
-	$cats[0]; // Take the first cat.
+	$cat_id = (int) $cats[0]; // Take the first cat.
 
 	$cat = get_category($cat_id);
 	return $cat->cat_name;
diff --git a/wp-includes/category-template.php b/wp-includes/category-template.php
index c1aabf543c..df102b5cdf 100644
--- a/wp-includes/category-template.php
+++ b/wp-includes/category-template.php
@@ -64,8 +64,7 @@ global $post, $category_cache, $blog_id;
 
 	$id = (int) $id;
 	if ( !$id )
-		$id = (int) 
-		$post->ID;
+		$id = (int) $post->ID;
 
 	if ( !isset($category_cache[$blog_id][$id]) )
 		update_post_category_cache($id);
diff --git a/wp-includes/post.php b/wp-includes/post.php
index 20ab78bccf..d747695204 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -643,7 +643,7 @@ function wp_insert_post($postarr = array()) {
 			(post_author, post_date, post_date_gmt, post_content, post_content_filtered, post_title, post_excerpt,  post_status, post_type, comment_status, ping_status, post_password, post_name, to_ping, pinged, post_modified, post_modified_gmt, post_parent, menu_order, post_mime_type)
 			VALUES
 			('$post_author', '$post_date', '$post_date_gmt', '$post_content', '$post_content_filtered', '$post_title', '$post_excerpt', '$post_status', '$post_type', '$comment_status', '$ping_status', '$post_password', '$post_name', '$to_ping', '$pinged', '$post_date', '$post_date_gmt', '$post_parent', '$menu_order', '$post_mime_type')");
-			$post_ID = $wpdb->insert_id;
+			$post_ID = (int) $wpdb->insert_id;
 	}
 
 	if ( empty($post_name) && 'draft' != $post_status ) {
@@ -1351,7 +1351,7 @@ function wp_insert_attachment($object, $file = false, $post_parent = 0) {
 			(post_author, post_date, post_date_gmt, post_content, post_content_filtered, post_title, post_excerpt,  post_status, post_type, comment_status, ping_status, post_password, post_name, to_ping, pinged, post_modified, post_modified_gmt, post_parent, menu_order, post_mime_type, guid)
 			VALUES
 			('$post_author', '$post_date', '$post_date_gmt', '$post_content', '$post_content_filtered', '$post_title', '$post_excerpt', '$post_status', '$post_type', '$comment_status', '$ping_status', '$post_password', '$post_name', '$to_ping', '$pinged', '$post_date', '$post_date_gmt', '$post_parent', '$menu_order', '$post_mime_type', '$guid')");
-			$post_ID = $wpdb->insert_id;
+			$post_ID = (int) $wpdb->insert_id;
 	}
 
 	if ( empty($post_name) ) {