#4892 SQL Server :schema list reading fix (avoid sub-queries)

plugins/org.jkiss.dbeaver.ext.mssql/src/org/jkiss/dbeaver/ext/mssql/model/SQLServerDatabase.java

@@ -273,18 +273,21 @@ public class SQLServerDatabase implements DBSCatalog, DBPSaveableObject, DBPRefr
 
             String sysSchema = SQLServerUtils.getSystemSchemaFQN(dataSource, owner.getName(), SQLServerConstants.SQL_SERVER_SYSTEM_SCHEMA);
             StringBuilder sql = new StringBuilder();
-            sql.append("SELECT s.*,ep.value as description FROM ").append(sysSchema).append(".schemas s");
-            sql.append("\nLEFT OUTER JOIN ").append(SQLServerUtils.getExtendedPropsTableName(owner)).append(" ep ON ep.class=").append(SQLServerObjectClass.SCHEMA.getClassId()).append(" AND ep.major_id=s.schema_id AND ep.minor_id=0 AND ep.name='").append(SQLServerConstants.PROP_MS_DESCRIPTION).append("'");
-            sql.append("\nWHERE ");
+            sql.append("SELECT ");
             if (!showAllSchemas) {
-                sql.append("EXISTS (SELECT 1 FROM ")
-                    .append(sysSchema).append(".sysobjects o ").append("WHERE s.schema_id=o.uid)");
-            } else {
-                sql.append("1=1");
+                sql.append("DISTINCT ");
+            }
+            sql.append("s.*,ep.value as description FROM ").append(sysSchema).append(".schemas s");
+            sql.append("\nLEFT OUTER JOIN ").append(SQLServerUtils.getExtendedPropsTableName(owner)).append(" ep ON ep.class=").append(SQLServerObjectClass.SCHEMA.getClassId())
+                .append(" AND ep.major_id=s.schema_id AND ep.minor_id=0 AND ep.name='").append(SQLServerConstants.PROP_MS_DESCRIPTION).append("'");
+            if (!showAllSchemas) {
+                sql.append("\nINNER JOIN ")
+                    .append(sysSchema).append(".sysobjects o ").append("ON s.schema_id=o.uid");
             }
             final DBSObjectFilter schemaFilters = dataSource.getContainer().getObjectFilter(SQLServerSchema.class, owner, false);
             if (schemaFilters != null && schemaFilters.isEnabled()) {
-                JDBCUtils.appendFilterClause(sql, schemaFilters, "s.name", false);
+                sql.append("\nWHERE ");
+                JDBCUtils.appendFilterClause(sql, schemaFilters, "s.name", true);
             }
 
             JDBCPreparedStatement dbStat = session.prepareStatement(sql.toString());