Golang expressions.EvalBoolExpr函数代码示例

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本文整理汇总了Golang中github.com/pingcap/tidb/expression/expressions.EvalBoolExpr函数的典型用法代码示例。如果您正苦于以下问题：Golang EvalBoolExpr函数的具体用法？Golang EvalBoolExpr怎么用？Golang EvalBoolExpr使用的例子？那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。

在下文中一共展示了EvalBoolExpr函数的9个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于我们的系统推荐出更棒的Golang代码示例。

示例1: Do

// Do implements plan.Plan Do interface.
// It scans rows over SrcPlan and check if it meets all conditions in Expr.
func (r *HavingPlan) Do(ctx context.Context, f plan.RowIterFunc) (err error) {
	m := map[interface{}]interface{}{}

	return r.Src.Do(ctx, func(rid interface{}, in []interface{}) (more bool, err error) {
		m[expressions.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
			return getIdentValue(name, r.Src.GetFields(), in, field.CheckFieldFlag)
		}

		m[expressions.ExprEvalPositionFunc] = func(position int) (interface{}, error) {
			// position is in [1, len(fields)], so we must decrease 1 to get correct index
			// TODO: check position invalidation
			return in[position-1], nil
		}

		v, err := expressions.EvalBoolExpr(ctx, r.Expr, m)

		if err != nil {
			return false, err
		}

		if !v {
			return true, nil
		}

		return f(rid, in)
	})
}

开发者ID:superwood，项目名称:tidb，代码行数:29，代码来源:having.go

示例2: Next

// Next implements plan.Plan Next interface.
func (r *HavingPlan) Next(ctx context.Context) (row *plan.Row, err error) {
	if r.evalArgs == nil {
		r.evalArgs = map[interface{}]interface{}{}
	}
	for {
		var srcRow *plan.Row
		srcRow, err = r.Src.Next(ctx)
		if srcRow == nil || err != nil {
			return nil, errors.Trace(err)
		}
		r.evalArgs[expressions.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
			return getIdentValue(name, r.Src.GetFields(), srcRow.Data, field.CheckFieldFlag)
		}
		r.evalArgs[expressions.ExprEvalPositionFunc] = func(position int) (interface{}, error) {
			// position is in [1, len(fields)], so we must decrease 1 to get correct index
			// TODO: check position invalidation
			return srcRow.Data[position-1], nil
		}
		var v bool
		v, err = expressions.EvalBoolExpr(ctx, r.Expr, r.evalArgs)
		if err != nil {
			return nil, errors.Trace(err)
		}
		if v {
			row = srcRow
			return
		}
	}
}

开发者ID:superwood，项目名称:tidb，代码行数:30，代码来源:having.go

示例3: doCrossJoin

func (r *JoinPlan) doCrossJoin(ctx context.Context, f plan.RowIterFunc) error {
	return r.Left.Do(ctx, func(rid interface{}, in []interface{}) (more bool, err error) {
		leftRow := appendRow(nil, in)
		m := map[interface{}]interface{}{}
		if err := r.Right.Do(ctx, func(rid interface{}, in []interface{}) (more bool, err error) {
			row := appendRow(leftRow, in)
			if r.On != nil {
				m[expressions.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
					return getIdentValue(name, r.Fields, row, field.DefaultFieldFlag)
				}

				b, err := expressions.EvalBoolExpr(ctx, r.On, m)
				if err != nil {
					return false, err
				}
				if !b {
					// If On condition not satisified, drop this row
					return true, nil
				}
			}

			return f(rid, row)
		}); err != nil {
			return false, err
		}

		return true, nil
	})
}

开发者ID:szctop，项目名称:tidb，代码行数:29，代码来源:join.go

示例4: findMatchedRows

func (r *JoinPlan) findMatchedRows(ctx context.Context, row *plan.Row, right bool) (err error) {
	var p plan.Plan
	if right {
		p = r.Left
	} else {
		p = r.Right
	}
	r.cursor = 0
	r.matchedRows = nil
	p.Close()
	for {
		var cmpRow *plan.Row
		cmpRow, err = p.Next(ctx)
		if err != nil {
			return errors.Trace(err)
		}
		if cmpRow == nil {
			break
		}
		var joined []interface{}
		if right {
			joined = append(cmpRow.Data, row.Data...)
		} else {
			joined = append(row.Data, cmpRow.Data...)
		}
		r.evalArgs[expressions.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
			return GetIdentValue(name, r.Fields, joined, field.DefaultFieldFlag)
		}
		var b bool
		b, err = expressions.EvalBoolExpr(ctx, r.On, r.evalArgs)
		if err != nil {
			return errors.Trace(err)
		}
		if b {
			cmpRow.Data = joined
			cmpRow.RowKeys = append(row.RowKeys, cmpRow.RowKeys...)
			r.matchedRows = append(r.matchedRows, cmpRow)
		}
	}
	if len(r.matchedRows) == 0 {
		if right {
			leftLen := len(r.Fields) - len(r.Right.GetFields())
			row.Data = append(make([]interface{}, leftLen), row.Data...)
		} else {
			rightLen := len(r.Fields) - len(r.Left.GetFields())
			row.Data = append(row.Data, make([]interface{}, rightLen)...)
		}
		r.matchedRows = append(r.matchedRows, row)
	}
	return nil
}

开发者ID:studygolang，项目名称:tidb，代码行数:51，代码来源:join.go

示例5: hitWhere

func (s *DeleteStmt) hitWhere(ctx context.Context, t table.Table, data []interface{}) (bool, error) {
	if s.Where == nil {
		return true, nil
	}
	m := map[interface{}]interface{}{}

	// Set parameter for evaluating expression.
	for _, col := range t.Cols() {
		m[col.Name.L] = data[col.Offset]
	}
	ok, err := expressions.EvalBoolExpr(ctx, s.Where, m)
	if err != nil {
		return false, errors.Trace(err)
	}
	return ok, nil
}

开发者ID:baotingfang，项目名称:tidb，代码行数:16，代码来源:delete.go

示例6: doFullJoin

func (r *JoinPlan) doFullJoin(ctx context.Context, f plan.RowIterFunc) error {
	// we just support full join simplify, because MySQL doesn't support it
	// for full join, we can use two phases
	// 1, t1 LEFT JOIN t2
	// 2, t2 anti semi LEFT JOIN t1
	if err := r.doLeftJoin(ctx, f); err != nil {
		return err
	}

	// anti semi left join
	return r.Right.Do(ctx, func(rid interface{}, in []interface{}) (more bool, err error) {
		rightRow := appendRow(nil, in)
		matched := false
		m := map[interface{}]interface{}{}
		if err := r.Left.Do(ctx, func(rid interface{}, in []interface{}) (more bool, err error) {
			row := appendRow(in, rightRow)

			m[expressions.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
				return getIdentValue(name, r.Fields, row, field.DefaultFieldFlag)
			}

			b, err := expressions.EvalBoolExpr(ctx, r.On, m)
			if err != nil {
				return false, err
			}
			if b {
				// here means the condition matched, we can skip this row
				matched = true
				return false, nil
			}

			return true, nil
		}); err != nil {
			return false, err
		}

		if !matched {
			// Fill left with NULL
			leftLen := len(r.Fields) - len(r.Right.GetFields())
			return f(rid, appendRow(make([]interface{}, leftLen), rightRow))
		}

		return true, nil
	})
}

开发者ID:szctop，项目名称:tidb，代码行数:45，代码来源:join.go

示例7: nextCrossJoin

func (r *JoinPlan) nextCrossJoin(ctx context.Context) (row *plan.Row, err error) {
	for {
		if r.curRow == nil {
			r.curRow, err = r.Left.Next(ctx)
			if err != nil {
				return nil, errors.Trace(err)
			}
			if r.curRow == nil {
				return nil, nil
			}
		}
		var rightRow *plan.Row
		rightRow, err = r.Right.Next(ctx)
		if err != nil {
			return nil, errors.Trace(err)
		}
		if rightRow == nil {
			r.curRow = nil
			r.Right.Close()
			continue
		}
		joinedRow := append(r.curRow.Data, rightRow.Data...)
		if r.On != nil {
			r.evalArgs[expressions.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
				return GetIdentValue(name, r.Fields, joinedRow, field.DefaultFieldFlag)
			}

			b, err := expressions.EvalBoolExpr(ctx, r.On, r.evalArgs)
			if err != nil {
				return nil, errors.Trace(err)
			}
			if !b {
				// If On condition not satisified, drop this row
				continue
			}
		}
		row = &plan.Row{
			Data:    joinedRow,
			RowKeys: append(r.curRow.RowKeys, rightRow.RowKeys...),
		}
		return
	}
}

开发者ID:studygolang，项目名称:tidb，代码行数:43，代码来源:join.go

示例8: doRightJoin

func (r *JoinPlan) doRightJoin(ctx context.Context, f plan.RowIterFunc) error {
	// right join is the same as left join, only reverse the row result
	return r.Right.Do(ctx, func(rid interface{}, in []interface{}) (more bool, err error) {
		rightRow := appendRow(nil, in)
		matched := false
		m := map[interface{}]interface{}{}
		if err := r.Left.Do(ctx, func(rid interface{}, in []interface{}) (more bool, err error) {
			row := appendRow(in, rightRow)

			m[expressions.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
				return getIdentValue(name, r.Fields, row, field.DefaultFieldFlag)
			}

			b, err := expressions.EvalBoolExpr(ctx, r.On, m)
			if err != nil {
				return false, err
			}
			if !b {
				return true, nil
			}

			matched = true

			return f(rid, row)
		}); err != nil {
			return false, err
		}

		if !matched {
			// Fill left with NULL
			leftLen := len(r.Fields) - len(r.Right.GetFields())
			return f(rid, appendRow(make([]interface{}, leftLen), rightRow))
		}

		return true, nil
	})
}

开发者ID:szctop，项目名称:tidb，代码行数:37，代码来源:join.go

示例9: fetchAll


//.........这里部分代码省略.........
		cols := tb.Cols()

		for _, col := range cols {
			if !s.isColOK(col) {
				continue
			}

			desc := column.NewColDesc(col)

			// The FULL keyword causes the output to include the column collation and comments,
			// as well as the privileges you have for each column.
			row := &plan.Row{}
			if s.Full {
				row.Data = []interface{}{
					desc.Field,
					desc.Type,
					desc.Collation,
					desc.Null,
					desc.Key,
					desc.DefaultValue,
					desc.Extra,
					desc.Privileges,
					desc.Comment,
				}
			} else {
				row.Data = []interface{}{
					desc.Field,
					desc.Type,
					desc.Null,
					desc.Key,
					desc.DefaultValue,
					desc.Extra,
				}
			}
			s.rows = append(s.rows, row)
		}
	case stmt.ShowWarnings:
	// empty result
	case stmt.ShowCharset:
		// See: http://dev.mysql.com/doc/refman/5.7/en/show-character-set.html
		descs := charset.GetAllCharsets()
		for _, desc := range descs {
			row := &plan.Row{
				Data: []interface{}{desc.Name, desc.Desc, desc.DefaultCollation, desc.Maxlen},
			}
			s.rows = append(s.rows, row)
		}
	case stmt.ShowVariables:
		sessionVars := variable.GetSessionVars(ctx)
		for _, v := range variable.SysVars {
			if s.Pattern != nil {
				p, ok := s.Pattern.(*expressions.PatternLike)
				if !ok {
					return errors.Errorf("Like should be a PatternLike expression")
				}
				p.Expr = expressions.Value{Val: v.Name}
				r, err := p.Eval(ctx, nil)
				if err != nil {
					return errors.Trace(err)
				}
				match, ok := r.(bool)
				if !ok {
					return errors.Errorf("Eval like pattern error")
				}
				if !match {
					continue
				}
			} else if s.Where != nil {
				m := map[interface{}]interface{}{}

				m[expressions.ExprEvalIdentFunc] = func(name string) (interface{}, error) {
					if strings.EqualFold(name, "Variable_name") {
						return v.Name, nil
					}

					return nil, errors.Errorf("unknown field %s", name)
				}

				match, err := expressions.EvalBoolExpr(ctx, s.Where, m)
				if err != nil {
					return errors.Trace(err)
				}
				if !match {
					continue
				}
			}
			value := v.Value
			if !s.GlobalScope {
				// Try to get Session Scope variable value
				sv, ok := sessionVars.Systems[v.Name]
				if ok {
					value = sv
				}
			}
			row := &plan.Row{Data: []interface{}{v.Name, value}}
			s.rows = append(s.rows, row)
		}
	}
	return nil
}

开发者ID:hxiaodon，项目名称:tidb，代码行数:101，代码来源:show.go

注：本文中的github.com/pingcap/tidb/expression/expressions.EvalBoolExpr函数示例由纯净天空整理自Github/MSDocs等源码及文档管理平台，相关代码片段筛选自各路编程大神贡献的开源项目，源码版权归原作者所有，传播和使用请参考对应项目的License；未经允许，请勿转载。