C# Parse.MayAbort方法代码示例

        public static void RenameTable(Parse parse, SrcList src, Token name)
        {
            Context ctx = parse.Ctx; // Database connection

            Context.FLAG savedDbFlags = ctx.Flags; // Saved value of db->flags
            //if (C._NEVER(ctx.MallocFailed)) goto exit_rename_table;
            Debug.Assert(src.Srcs == 1);
            Debug.Assert(Btree.HoldsAllMutexes(ctx));

            Table table = parse.LocateTableItem(false, src.Ids[0]); // Table being renamed
            if (table == null) goto exit_rename_table;
            int db = Prepare.SchemaToIndex(ctx, table.Schema); // Database that contains the table
            string dbName = ctx.DBs[db].Name; // Name of database iDb
            ctx.Flags |= Context.FLAG.PreferBuiltin;

            // Get a NULL terminated version of the new table name.
            string nameAsString = Parse.NameFromToken(ctx, name); // NULL-terminated version of pName
            if (nameAsString == null) goto exit_rename_table;

            // Check that a table or index named 'zName' does not already exist in database iDb. If so, this is an error.
            if (Parse.FindTable(ctx, nameAsString, dbName) != null || Parse.FindIndex(ctx, nameAsString, dbName) != null)
            {
                parse.ErrorMsg("there is already another table or index with this name: %s", nameAsString);
                goto exit_rename_table;
            }

            // Make sure it is not a system table being altered, or a reserved name that the table is being renamed to.
            if (IsSystemTable(parse, table.Name) || parse->CheckObjectName(nameAsString) != RC.OK)
                goto exit_rename_table;

#if !OMIT_VIEW
            if (table.Select != null)
            {
                parse.ErrorMsg("view %s may not be altered", table.Name);
                goto exit_rename_table;
            }
#endif

#if !OMIT_AUTHORIZATION
            // Invoke the authorization callback.
            if (Auth.Check(parse, AUTH.ALTER_TABLE, dbName, table.Name, null))
                goto exit_rename_table;
#endif

            VTable vtable = null; // Non-zero if this is a v-tab with an xRename()
#if !OMIT_VIRTUALTABLE
            if (parse->ViewGetColumnNames(table) != 0)
                goto exit_rename_table;
            if (E.IsVirtual(table))
            {
                vtable = VTable.GetVTable(ctx, table);
                if (vtable.IVTable.IModule.Rename == null)
                    vtable = null;
            }
#endif

            // Begin a transaction and code the VerifyCookie for database iDb. Then modify the schema cookie (since the ALTER TABLE modifies the
            // schema). Open a statement transaction if the table is a virtual table.
            Vdbe v = parse.GetVdbe();
            if (v == null) goto exit_rename_table;
            parse.BeginWriteOperation((vtable != null ? 1 : 0), db);
            parse.ChangeCookie(db);

            // If this is a virtual table, invoke the xRename() function if one is defined. The xRename() callback will modify the names
            // of any resources used by the v-table implementation (including other SQLite tables) that are identified by the name of the virtual table.
#if  !OMIT_VIRTUALTABLE
            if (vtable != null)
            {
                int i = ++parse.Mems;
                v.AddOp4(OP.String8, 0, i, 0, nameAsString, 0);
                v.AddOp4(OP.VRename, i, 0, 0, vtable, Vdbe.P4T.VTAB);
                parse.MayAbort();
            }
#endif

            // figure out how many UTF-8 characters are in zName
            string tableName = table.Name; // Original name of the table
            int tableNameLength = C._utf8charlength(tableName, -1); // Number of UTF-8 characters in zTabName

#if !OMIT_TRIGGER
            string where_ = string.Empty; // Where clause to locate temp triggers
#endif

#if !OMIT_FOREIGN_KEY && !OMIT_TRIGGER
            if ((ctx.Flags & Context.FLAG.ForeignKeys) != 0)
            {
                // If foreign-key support is enabled, rewrite the CREATE TABLE statements corresponding to all child tables of foreign key constraints
                // for which the renamed table is the parent table.
                if ((where_ = WhereForeignKeys(parse, table)) != null)
                {
                    parse.NestedParse(
                        "UPDATE \"%w\".%s SET " +
                            "sql = sqlite_rename_parent(sql, %Q, %Q) " +
                            "WHERE %s;", dbName, E.SCHEMA_TABLE(db), tableName, nameAsString, where_);
                    C._tagfree(ctx, ref where_);
                }
            }
#endif

            // Modify the sqlite_master table to use the new table name.
//.........这里部分代码省略.........