From 200f0ad20f48c3a4d7d6731b38a92d29cfb7d847 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Gerg=C5=91=20Tisza?= <tgr.huwiki@gmail.com>
Date: Sun, 16 Dec 2018 21:55:04 -0800
Subject: [PATCH] Make sql.php exit status more informative

Add a --status option which sets nonzero exit status for a query
returning or updating no rows. This is useful for shell scripts which
want to do simple existence checks (e.g. 'unless' conditions in Puppet)
or need to do a single-row change.

Change-Id: I3988c4fb24251dd8b33ac85aed9d0ae03eb0f910
---
 maintenance/sql.php | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/maintenance/sql.php b/maintenance/sql.php
index dba4a223a7..6a4cf0426b 100644
--- a/maintenance/sql.php
+++ b/maintenance/sql.php
@@ -42,6 +42,8 @@ class MwSql extends Maintenance {
 		$this->addOption( 'query',
 			'Run a single query instead of running interactively', false, true );
 		$this->addOption( 'json', 'Output the results as JSON instead of PHP objects' );
+		$this->addOption( 'status', 'Return successful exit status only if the query succeeded '
+			. '(selected or altered rows), otherwise 1 for errors, 2 for no rows' );
 		$this->addOption( 'cluster', 'Use an external cluster by name', false, true );
 		$this->addOption( 'wikidb',
 			'The database wiki ID to use if not the current one', false, true );
@@ -108,8 +110,11 @@ class MwSql extends Maintenance {
 
 		if ( $this->hasOption( 'query' ) ) {
 			$query = $this->getOption( 'query' );
-			$this->sqlDoQuery( $db, $query, /* dieOnError */ true );
+			$res = $this->sqlDoQuery( $db, $query, /* dieOnError */ true );
 			wfWaitForSlaves();
+			if ( $this->hasOption( 'status' ) ) {
+				exit( $res ? 0 : 2 );
+			}
 			return;
 		}
 
@@ -128,6 +133,7 @@ class MwSql extends Maintenance {
 		$newPrompt = '> ';
 		$prompt = $newPrompt;
 		$doDie = !Maintenance::posix_isatty( 0 );
+		$res = 1;
 		while ( ( $line = Maintenance::readconsole( $prompt ) ) !== false ) {
 			if ( !$line ) {
 				# User simply pressed return key
@@ -148,17 +154,26 @@ class MwSql extends Maintenance {
 				readline_add_history( $wholeLine . ';' );
 				readline_write_history( $historyFile );
 			}
-			$this->sqlDoQuery( $db, $wholeLine, $doDie );
+			$res = $this->sqlDoQuery( $db, $wholeLine, $doDie );
 			$prompt = $newPrompt;
 			$wholeLine = '';
 		}
 		wfWaitForSlaves();
+		if ( $this->hasOption( 'status' ) ) {
+			exit( $res ? 0 : 2 );
+		}
 	}
 
+	/**
+	 * @param IDatabase $db
+	 * @param string $line The SQL text of the query
+	 * @param bool $dieOnError
+	 * @return int|null Number of rows selected or updated, or null if the query was unsuccessful.
+	 */
 	protected function sqlDoQuery( IDatabase $db, $line, $dieOnError ) {
 		try {
 			$res = $db->query( $line );
-			$this->sqlPrintResult( $res, $db );
+			return $this->sqlPrintResult( $res, $db );
 		} catch ( DBQueryError $e ) {
 			if ( $dieOnError ) {
 				$this->fatalError( $e );
@@ -166,17 +181,19 @@ class MwSql extends Maintenance {
 				$this->error( $e );
 			}
 		}
+		return null;
 	}
 
 	/**
 	 * Print the results, callback for $db->sourceStream()
 	 * @param ResultWrapper|bool $res
 	 * @param IDatabase $db
+	 * @return int|null Number of rows selected or updated, or null if the query was unsuccessful.
 	 */
 	public function sqlPrintResult( $res, $db ) {
 		if ( !$res ) {
 			// Do nothing
-			return;
+			return null;
 		} elseif ( is_object( $res ) ) {
 			$out = '';
 			$rows = [];
@@ -190,6 +207,7 @@ class MwSql extends Maintenance {
 				$out = 'Query OK, 0 row(s) affected';
 			}
 			$this->output( $out . "\n" );
+			return count( $rows );
 		} else {
 			$affected = $db->affectedRows();
 			if ( $this->hasOption( 'json' ) ) {
@@ -197,6 +215,7 @@ class MwSql extends Maintenance {
 			} else {
 				$this->output( "Query OK, $affected row(s) affected\n" );
 			}
+			return $affected;
 		}
 	}
 
-- 
2.20.1