diff --git a/sql/cambios.sql b/sql/cambios.sql
index 15e70acfa..971caf3b3 100644
--- a/sql/cambios.sql
+++ b/sql/cambios.sql
@@ -11679,7 +11679,7 @@ UPDATE surveys SET Cod=CrsCod WHERE Scope='Crs';
 DROP INDEX DegCod ON surveys;
 ALTER TABLE surveys ADD PRIMARY KEY(SvyCod);
 DROP INDEX SvyCod ON surveys;
-ALTER TABLE surveys ADD UNIQUE INDEX(SvyCod,Scope,Cod,Hidden),ADD INDEX(Scope,Cod,Hidden);
+ALTER TABLE surveys ADD UNIQUE INDEX(Scope,Cod);
 
 
 ----- TODO: Eliminar columnas sin uso en futuras versiones -----
diff --git a/sql/swad.sql b/sql/swad.sql
index 902d35b8b..18b7af1e8 100644
--- a/sql/swad.sql
+++ b/sql/swad.sql
@@ -989,8 +989,8 @@ CREATE TABLE IF NOT EXISTS sta_notif (
 --
 CREATE TABLE IF NOT EXISTS surveys (
 	SvyCod INT NOT NULL AUTO_INCREMENT,
-	DegCod INT NOT NULL DEFAULT -1,
-	CrsCod INT NOT NULL DEFAULT -1,
+	Scope ENUM('Sys','Cty','Ins','Ctr','Deg','Crs') NOT NULL DEFAULT 'Sys',
+	Cod INT NOT NULL DEFAULT -1,
 	Hidden ENUM('N','Y') NOT NULL DEFAULT 'N',
 	NumNotif INT NOT NULL DEFAULT 0,
 	Roles INT NOT NULL DEFAULT 0,
@@ -1000,7 +1000,7 @@ CREATE TABLE IF NOT EXISTS surveys (
 	Title VARCHAR(255) NOT NULL,
 	Txt TEXT NOT NULL,
 	UNIQUE INDEX(SvyCod),
-	INDEX(DegCod,CrsCod,Hidden));
+	INDEX(Scope,Cod));
 --
 -- Table svy_answers: stores the answers to the surveys
 --
diff --git a/swad_changelog.h b/swad_changelog.h
index 6a54be6cd..753152529 100644
--- a/swad_changelog.h
+++ b/swad_changelog.h
@@ -154,15 +154,16 @@
 /****************************** Public constants *****************************/
 /*****************************************************************************/
 
-#define Log_PLATFORM_VERSION	"SWAD 16.45 (2016-10-27)"
+#define Log_PLATFORM_VERSION	"SWAD 16.45.1 (2016-10-27)"
 #define CSS_FILE		"swad16.32.1.css"
 #define JS_FILE			"swad15.238.1.js"
 
 // Number of lines (includes comments but not blank lines) has been got with the following command:
 // nl swad*.c swad*.h css/swad*.css py/swad*.py js/swad*.js soap/swad*.h sql/swad*.sql | tail -1
 /*
+        Version 16.45.1:  Oct 27, 2016	Fixed bugs in surveys. (? lines)
         Version 16.45:    Oct 27, 2016	Changes in database table for surveys. Not finished. (205927 lines)
-					12 changes necessary in database:
+					10 changes necessary in database:
 ALTER TABLE surveys ADD COLUMN Scope ENUM('Sys','Cty','Ins','Ctr','Deg','Crs') NOT NULL DEFAULT 'Sys' AFTER SvyCod;
 ALTER TABLE surveys ADD COLUMN Cod INT NOT NULL DEFAULT -1 AFTER Scope;
 
@@ -175,9 +176,7 @@ UPDATE surveys SET Cod=DegCod WHERE Scope='Deg';
 UPDATE surveys SET Cod=CrsCod WHERE Scope='Crs';
 
 DROP INDEX DegCod ON surveys;
-ALTER TABLE surveys ADD PRIMARY KEY(SvyCod);
-DROP INDEX SvyCod ON surveys;
-ALTER TABLE surveys ADD UNIQUE INDEX(SvyCod,Scope,Cod,Hidden),ADD INDEX(Scope,Cod,Hidden);
+ALTER TABLE surveys ADD INDEX(Scope,Cod);
 
         Version 16.44:    Oct 27, 2016	New scopes (centre, institution, country) of surveys. Not finished. (205826 lines)
         Version 16.43:    Oct 26, 2016	Fixed bugs and code refactoring in scope of surveys. (205537 lines)
diff --git a/swad_database.c b/swad_database.c
index dd16a0c4a..517d84826 100644
--- a/swad_database.c
+++ b/swad_database.c
@@ -2109,8 +2109,6 @@ mysql> DESCRIBE surveys;
                    "SvyCod INT NOT NULL AUTO_INCREMENT,"
 	           "Scope ENUM('Sys','Cty','Ins','Ctr','Deg','Crs') NOT NULL DEFAULT 'Sys',"
 	           "Cod INT NOT NULL DEFAULT -1,"
-		      "DegCod INT NOT NULL DEFAULT -1,"	// TODO: DROP COLUMN
-		      "CrsCod INT NOT NULL DEFAULT -1,"	// TODO: DROP COLUMN
                    "Hidden ENUM('N','Y') NOT NULL DEFAULT 'N',"
                    "NumNotif INT NOT NULL DEFAULT 0,"
                    "Roles INT NOT NULL DEFAULT 0,"
@@ -2119,9 +2117,8 @@ mysql> DESCRIBE surveys;
                    "EndTime DATETIME NOT NULL,"
                    "Title VARCHAR(255) NOT NULL,"
                    "Txt TEXT NOT NULL,"
-                   "PRIMARY KEY(SvyCod),"
-	           "UNIQUE INDEX(SvyCod,Scope,Cod,Hidden),"
-	           "INDEX(Scope,Cod,Hidden))");
+                   "UNIQUE INDEX(SvyCod),"
+	           "INDEX(Scope,Cod)");
 
    /***** Table svy_answers *****/
 /*
diff --git a/swad_survey.c b/swad_survey.c
index 4eec1351d..f485463f3 100644
--- a/swad_survey.c
+++ b/swad_survey.c
@@ -843,6 +843,7 @@ static void Svy_PutParams (void)
 
 void Svy_GetListSurveys (void)
   {
+   extern const char *Sco_ScopeDB[Sco_NUM_SCOPES];
    char SubQuery[Sco_NUM_SCOPES][128];
    char OrderBySubQuery[256];
    char Query[2048];
@@ -872,14 +873,14 @@ void Svy_GetListSurveys (void)
    Cods[Sco_SCOPE_CRS] = Gbl.CurrentCrs.Crs.CrsCod;	// Course
 
    for (Scope = Sco_SCOPE_SYS, SubQueryFilled = false;
-	Scope < Sco_SCOPE_CRS;
+	Scope <= Sco_SCOPE_CRS;
 	Scope++)
       if (ScopesAllowed & 1 << Scope)
 	{
-	 sprintf (SubQuery[Scope],"%s(Scope='%u' AND Cod='%ld'%s)",
+	 sprintf (SubQuery[Scope],"%s(Scope='%s' AND Cod='%ld'%s)",
 	          SubQueryFilled ? " OR " :
 	        	           "",
-		  (unsigned) Scope,Cods[Scope],
+		  Sco_ScopeDB[Scope],Cods[Scope],
 		  (ScopesAllowed & 1 << Sco_SCOPE_SYS) ? "" :
 							 " AND Hidden='N'");
 	 SubQueryFilled = true;