CovenantSQL · auxten · Nov 22, 2018 · Nov 25, 2018 · Nov 27, 2018 · Nov 27, 2018
diff --git a/blockproducer/metastate.go b/blockproducer/metastate.go
@@ -19,6 +19,9 @@ package blockproducer
 import (
 	"time"
 
+	"github.com/pkg/errors"
+	"github.com/ulule/deepcopier"
+
 	pi "github.com/CovenantSQL/CovenantSQL/blockproducer/interfaces"
 	"github.com/CovenantSQL/CovenantSQL/crypto"
 	"github.com/CovenantSQL/CovenantSQL/crypto/asymmetric"
@@ -27,8 +30,6 @@ import (
 	"github.com/CovenantSQL/CovenantSQL/proto"
 	"github.com/CovenantSQL/CovenantSQL/types"
 	"github.com/CovenantSQL/CovenantSQL/utils/log"
-	"github.com/pkg/errors"
-	"github.com/ulule/deepcopier"
 )
 
 var (

diff --git a/client/_example/gdpaverage.go b/client/_example/gdpaverage.go
@@ -100,6 +100,7 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer rows.Close()
 	log.Printf("\nExec:\n %s\n", Q)
 	log.Println("ID	Name	CountryCode	District	Population")
 	var ID, GDP, Population int

diff --git a/shard/delete.go b/shard/delete.go
@@ -0,0 +1,120 @@
+/*
+ * Copyright 2018 The CovenantSQL Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package shard
+
+import (
+	"context"
+	"database/sql"
+	"database/sql/driver"
+	"sync"
+
+	"github.com/CovenantSQL/CovenantSQL/utils/log"
+	"github.com/CovenantSQL/sqlparser"
+	"github.com/pkg/errors"
+)
+
+// buildDeletePlan builds the route for an DELETE statement.
+func buildDeletePlan(query string,
+	del *sqlparser.Delete,
+	args []driver.NamedValue,
+	c *ShardingConn,
+) (instructions Primitive, err error) {
+	log.Debugf("buildDeletePlan got %s\n delete:%#v\n args: %#v", query, del, args)
+	if del.OrderBy != nil || del.Limit != nil {
+		return nil, errors.New("unsupported: OrderBy or LIMIT in DELETE")
+	}
+
+	if len(del.TableExprs) == 1 {
+		var (
+			tableExpr       *sqlparser.AliasedTableExpr
+			simpleTableExpr sqlparser.SimpleTableExpr
+			originTableName sqlparser.TableIdent
+			ok              bool
+		)
+		if tableExpr, ok = del.TableExprs[0].(*sqlparser.AliasedTableExpr); !ok {
+			return nil, errors.New("unsupported: FROM table type")
+		}
+		if simpleTableExpr, ok = tableExpr.Expr.(sqlparser.SimpleTableExpr); !ok {
+			return nil, errors.New("unsupported: FROM table type")
+		}
+		originTableName = sqlparser.GetTableName(simpleTableExpr)
+
+		if conf, ok := c.conf[originTableName.CompliantName()]; ok {
+			if !conf.ShardColName.IsEmpty() && conf.ShardInterval > 0 {
+
+				// split delete to shard tables
+				var shards []string
+				shards, err = c.getTableShards(originTableName.CompliantName())
+				delInstructions := &Delete{
+					Instructions: make([]*SinglePrimitive, len(shards)),
+				}
+
+				originFrom := del.TableExprs[0]
+				//TODO(auxten) deep copy a new delete is better
+				for i, shard := range shards {
+					del.TableExprs[0] = &sqlparser.AliasedTableExpr{
+						Expr: sqlparser.TableName{
+							Name:      sqlparser.NewTableIdent(shard),
+							Qualifier: sqlparser.TableIdent{},
+						},
+					}
+
+					buf := sqlparser.NewTrackedBuffer(nil)
+					del.Format(buf)
+					//FIXME(auxten) just use the same delete in shard table for now
+					fixedArgs := toNamedArgs(args)
+					delInstructions.Instructions[i] = &SinglePrimitive{
+						query:     buf.String(),
+						namedArgs: fixedArgs,
+						rawDB:     c.rawDB,
+					}
+				}
+				del.TableExprs[0] = originFrom
+				return delInstructions, nil
+
+			} else {
+				return nil, errors.Errorf("sharding conf set but not configured: %#v", conf)
+			}
+		} else {
+			// not sharding table
+		}
+	} else {
+		return nil, errors.Errorf("delete target must be 1: %s", query)
+	}
+
+	return &BasePrimitive{
+		query:   query,
+		args:    args,
+		rawConn: c.rawConn,
+		rawDB:   c.rawDB,
+	}, nil
+}
+
+type Delete struct {
+	sync.Mutex
+	Instructions []*SinglePrimitive
+}
+
+func (del *Delete) ExecContext(ctx context.Context, tx *sql.Tx) (driver.Result, error) {
+	del.Lock()
+	defer del.Unlock()
+	return execInstructionsTx(ctx, del.Instructions)
+}
+
+func (del *Delete) QueryContext(ctx context.Context) (driver.Rows, error) {
+	panic("should not call query in delete")
+}
diff --git a/shard/doc.go b/shard/doc.go
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2018 The CovenantSQL Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package shard
+
+/****** TODO List with order ******/
+
+// - Driver
+// 	- implement ShardingRows.Columns
+// 	- implement ShardingRows.Close
+// 	- implement ShardingRows.Next
+// - process auto increase column
+//  - "In other words, the purpose of AUTOINCREMENT is to prevent the reuse of ROWIDs from previously deleted rows."
+//  - we should change the primary key of first inserted row in shard table
+//  - SHARDCONF use json
+// - handle DDL query
+// - Optimize temp table create, current implementation copy too much to temp table