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FB-1827: Implement Len() (#2406)

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(cherry picked from commit f99be656df)
This commit is contained in:
rachithrr 2023-01-12 18:01:06 -05:00 • committed by Joe Friedrich
parent adbad90fe1
commit fc1b8fdfb8
4 changed files with 75 additions and 0 deletions
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2
sql3/planner/expression.go
View file

@ -1516,6 +1516,8 @@ func (n *callPlanExpression) Evaluate(currentRow []interface{}) (interface{}, er
return n.EvaluatePrefix(currentRow)
case "SPACE":
return n.EvaluateSpace(currentRow)
case "LEN":
return n.EvaluateLen(currentRow)
default:
return nil, sql3.NewErrInternalf("unhandled function name '%s'", n.name)
}

2
sql3/planner/expressionanalyzercall.go
View file

@ -269,6 +269,8 @@ func (p *ExecutionPlanner) analyzeCallExpression(call *parser.Call, scope parser
return p.analyseFunctionPrefixSuffix(call, scope)
case "SPACE":
return p.analyseFunctionSpace(call, scope)
case "LEN":
return p.analyseFunctionLen(call, scope)
default:
return nil, sql3.NewErrCallUnknownFunction(call.Name.NamePos.Line, call.Name.NamePos.Column, call.Name.Name)
}

32
sql3/planner/inbuiltfunctionsstring.go
View file

@ -195,6 +195,18 @@ func (p *ExecutionPlanner) analyseFunctionSpace(call *parser.Call, scope parser.
return call, nil
}
func (p *ExecutionPlanner) analyseFunctionLen(call *parser.Call, scope parser.Statement) (parser.Expr, error) {
if len(call.Args) != 1 {
return nil, sql3.NewErrCallParameterCountMismatch(call.Rparen.Line, call.Rparen.Column, call.Name.Name, 1, len(call.Args))
}
if !typeIsString(call.Args[0].DataType()) && !typeIsVoid(call.Args[0].DataType()) {
return nil, sql3.NewErrStringExpressionExpected(call.Args[0].Pos().Line, call.Args[0].Pos().Column)
}
call.ResultDataType = parser.NewDataTypeInt()
return call, nil
}
// reverses the string
func (n *callPlanExpression) EvaluateReverse(currentRow []interface{}) (interface{}, error) {
argEval, err := n.args[0].Evaluate(currentRow)
@ -264,6 +276,10 @@ func (n *callPlanExpression) EvaluateChar(currentRow []interface{}) (interface{}
if !ok {
return 0, sql3.NewErrInternalf("unexpected type converion %T", argEval)
}
// ascii range is [0-255]
if intArg < 0 || intArg > 255 {
return nil, sql3.NewErrValueOutOfRange(0, 0, intArg)
}
// Return the character that corresponds to the integer value
return string(rune(intArg)), nil
@ -580,3 +596,19 @@ func (n *callPlanExpression) EvaluateSpace(currentRow []interface{}) (interface{
}
return spaces, nil
}
func (n *callPlanExpression) EvaluateLen(currentRow []interface{}) (interface{}, error) {
argEval, err := n.args[0].Evaluate(currentRow)
if err != nil {
return nil, err
}
if argEval == nil {
return nil, nil
}
stringArg, ok := argEval.(string)
if !ok {
return nil, sql3.NewErrInternalf("unexpected type converion %T", argEval)
}
return int64(len([]rune(stringArg))), nil
}

39
sql3/test/defs/defs_string_functions.go
View file

@ -727,5 +727,44 @@ var stringScalarFunctionsTests = TableTest{
),
Compare: CompareExactOrdered,
},
{
name: "LenNull",
SQLs: sqls(
"select len(null)",
),
ExpHdrs: hdrs(
hdr("", fldTypeInt),
),
ExpRows: rows(
row(nil),
),
Compare: CompareExactOrdered,
},
{
name: "LenString",
SQLs: sqls(
"select len(' length ')",
),
ExpHdrs: hdrs(
hdr("", fldTypeInt),
),
ExpRows: rows(
row(int64(9)),
),
Compare: CompareExactOrdered,
},
{
name: "LenChar",
SQLs: sqls(
"select len(char(114))",
),
ExpHdrs: hdrs(
hdr("", fldTypeInt),
),
ExpRows: rows(
row(int64(1)),
),
Compare: CompareExactOrdered,
},
},
}