support INTERVAL type and AGE() function

postgres/messages/row_description.go

@@ -88,6 +88,8 @@ const (
 	OidTimestampArray    = 1115
 	OidDateArray         = 1182
 	OidTimeArray         = 1183
+	OidInterval          = 1186
+	OidIntervalArray     = 1187
 	OidNumeric           = 1700
 	OidRefcursor         = 1790
 	OidRegprocedure      = 2202

server/ast/expr.go

@@ -442,7 +442,15 @@ func nodeExpr(node tree.Expr) (vitess.Expr, error) {
 	case *tree.DInt:
 		return nil, fmt.Errorf("the statement is not yet supported")
 	case *tree.DInterval:
-		return nil, fmt.Errorf("the statement is not yet supported")
+		cast, err := pgexprs.NewExplicitCastInjectable(pgtypes.Interval)
+		if err != nil {
+			return nil, err
+		}
+		expr := pgexprs.NewIntervalLiteral(node.Duration)
+		return vitess.InjectedExpr{
+			Expression: cast,
+			Children:   vitess.Exprs{vitess.InjectedExpr{Expression: expr}},
+		}, nil
 	case *tree.DJSON:
 		return nil, fmt.Errorf("the statement is not yet supported")
 	case *tree.DOid:

server/ast/resolvable_type_reference.go

@@ -93,6 +93,8 @@ func nodeResolvableTypeReference(typ tree.ResolvableTypeReference) (*vitess.Conv
 				resolvedType = pgtypes.Int32
 			case oid.T_int8:
 				resolvedType = pgtypes.Int64
+			case oid.T_interval:
+				resolvedType = pgtypes.Interval
 			case oid.T_json:
 				resolvedType = pgtypes.Json
 			case oid.T_jsonb:

server/cast/init.go

@@ -24,6 +24,7 @@ func Init() {
 	initInt32()
 	initInt64()
 	initInternalChar()
+	initInterval()
 	initJson()
 	initJsonB()
 	initName()
@@ -33,5 +34,6 @@ func Init() {
 	initRegproc()
 	initRegtype()
 	initText()
+	initTime()
 	initVarChar()
 }

server/cast/internal_char.go

@@ -80,5 +80,4 @@ func internalCharImplicit() {
 			return val, nil
 		},
 	})
-
 }

server/cast/interval.go

@@ -0,0 +1,78 @@
+// Copyright 2024 Dolthub, Inc.
+//
+// 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 cast
+
+import (
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/postgres/parser/duration"
+
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// initInterval handles all casts that are built-in. This comprises only the "From" types.
+func initInterval() {
+	intervalAssignment()
+	intervalExplicit()
+	intervalImplicit()
+}
+
+// intervalAssignment registers all assignment casts. This comprises only the "From" types.
+func intervalAssignment() {
+	framework.MustAddAssignmentTypeCast(framework.TypeCast{
+		FromType: pgtypes.Interval,
+		ToType:   pgtypes.BpChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(duration.Duration).String(), targetType)
+		},
+	})
+	framework.MustAddAssignmentTypeCast(framework.TypeCast{
+		FromType: pgtypes.Interval,
+		ToType:   pgtypes.VarChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(duration.Duration).String(), targetType)
+		},
+	})
+}
+
+// intervalExplicit registers all implicit casts. This comprises only the "From" types.
+func intervalExplicit() {
+	framework.MustAddExplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.Interval,
+		ToType:   pgtypes.InternalChar,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(duration.Duration).String(), targetType)
+		},
+	})
+	framework.MustAddExplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.Interval,
+		ToType:   pgtypes.Name,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return handleStringCast(val.(duration.Duration).String(), targetType)
+		},
+	})
+}
+
+// intervalImplicit registers all implicit casts. This comprises only the "From" types.
+func intervalImplicit() {
+	framework.MustAddImplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.Interval,
+		ToType:   pgtypes.Text,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			return val.(duration.Duration).String(), nil
+		},
+	})
+}

server/cast/time.go

@@ -0,0 +1,43 @@
+// Copyright 2024 Dolthub, Inc.
+//
+// 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 cast
+
+import (
+	"time"
+
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/server/functions"
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// initTime handles all casts that are built-in. This comprises only the "From" types.
+func initTime() {
+	timeExplicit()
+}
+
+// timeExplicit registers all implicit casts. This comprises only the "From" types.
+func timeExplicit() {
+	framework.MustAddExplicitTypeCast(framework.TypeCast{
+		FromType: pgtypes.Time,
+		ToType:   pgtypes.Interval,
+		Function: func(ctx *sql.Context, val any, targetType pgtypes.DoltgresType) (any, error) {
+			t := val.(time.Time)
+			dur := functions.GetIntervalDurationFromTimeComponents(0, 0, 0, int64(t.Hour()), int64(t.Minute()), int64(t.Second()), int64(t.Nanosecond()))
+			return dur, nil
+		},
+	})
+}

server/expression/literal.go

@@ -23,6 +23,7 @@ import (
 	vitess "github.com/dolthub/vitess/go/vt/sqlparser"
 	"github.com/shopspring/decimal"
 
+	"github.com/dolthub/doltgresql/postgres/parser/duration"
 	"github.com/dolthub/doltgresql/server/functions/framework"
 	pgtypes "github.com/dolthub/doltgresql/server/types"
 )
@@ -88,6 +89,14 @@ func NewStringLiteral(stringValue string) *Literal {
 	}
 }
 
+// NewIntervalLiteral returns a new *Literal containing a INTERVAL value.
+func NewIntervalLiteral(duration duration.Duration) *Literal {
+	return &Literal{
+		value: duration,
+		typ:   pgtypes.Interval,
+	}
+}
+
 // NewJSONLiteral returns a new *Literal containing a JSON value. This is different from JSONB.
 func NewJSONLiteral(jsonValue string) *Literal {
 	return &Literal{

server/functions/age.go

@@ -0,0 +1,122 @@
+// Copyright 2024 Dolthub, Inc.
+//
+// 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 functions
+
+import (
+	"time"
+
+	"github.com/dolthub/go-mysql-server/sql"
+
+	"github.com/dolthub/doltgresql/postgres/parser/duration"
+	"github.com/dolthub/doltgresql/server/functions/framework"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// initAge registers the functions to the catalog.
+func initAge() {
+	framework.RegisterFunction(age_timestamp_timestamp)
+	framework.RegisterFunction(age_timestamp)
+}
+
+// age_timestamp_timestamp represents the PostgreSQL date/time function.
+var age_timestamp_timestamp = framework.Function2{
+	Name:               "age",
+	Return:             pgtypes.Interval,
+	Parameters:         [2]pgtypes.DoltgresType{pgtypes.Timestamp, pgtypes.Timestamp},
+	IsNonDeterministic: true,
+	Strict:             true,
+	Callable: func(ctx *sql.Context, _ [3]pgtypes.DoltgresType, val1, val2 any) (any, error) {
+		t1 := val1.(time.Time)
+		t2 := val2.(time.Time)
+		return diffTimes(t1, t2), nil
+	},
+}
+
+// age_timestamp_timestamp represents the PostgreSQL date/time function.
+var age_timestamp = framework.Function1{
+	Name:               "age",
+	Return:             pgtypes.Interval,
+	Parameters:         [1]pgtypes.DoltgresType{pgtypes.Timestamp},
+	IsNonDeterministic: true,
+	Strict:             true,
+	Callable: func(ctx *sql.Context, _ [2]pgtypes.DoltgresType, val any) (any, error) {
+		t := val.(time.Time)
+		// current_date (at midnight)
+		cur, err := time.Parse("2006-01-02", time.Now().Format("2006-01-02"))
+		if err != nil {
+			return nil, err
+		}
+		return diffTimes(cur, t), nil
+	},
+}
+
+// diffTimes returns the duration t1-t2. It subtracts each time component separately,
+// unlike time.Sub() function.
+func diffTimes(t1, t2 time.Time) duration.Duration {
+	// if t1 is before t2, then negate the result.
+	negate := t1.Before(t2)
+	if negate {
+		t1, t2 = t2, t1
+	}
+
+	// Calculate difference in each unit
+	years := int64(t1.Year() - t2.Year())
+	months := int64(t1.Month() - t2.Month())
+	days := int64(t1.Day() - t2.Day())
+	hours := int64(t1.Hour() - t2.Hour())
+	minutes := int64(t1.Minute() - t2.Minute())
+	seconds := int64(t1.Second() - t2.Second())
+	nanoseconds := int64(t1.Nanosecond() - t2.Nanosecond())
+
+	// Adjust for any negative values
+	if nanoseconds < 0 {
+		nanoseconds += 1e9
+		seconds--
+	}
+	if seconds < 0 {
+		seconds += 60
+		minutes--
+	}
+	if minutes < 0 {
+		minutes += 60
+		hours--
+	}
+	if hours < 0 {
+		hours += 24
+		days--
+	}
+	if days < 0 {
+		days += 30
+		months--
+	}
+	if months < 0 {
+		months += 12
+		years--
+	}
+
+	dur := GetIntervalDurationFromTimeComponents(years, months, days, hours, minutes, seconds, nanoseconds)
+	if negate {
+		return dur.Mul(-1)
+	}
+	return dur
+}
+
+func GetIntervalDurationFromTimeComponents(years, months, days, hours, minutes, seconds, nanos int64) duration.Duration {
+	durNanos := nanos + seconds*NanosPerSec + minutes*NanosPerSec*duration.SecsPerMinute + hours*NanosPerSec*duration.SecsPerHour
+	durDays := days
+	durMonths := months + years*duration.MonthsPerYear
+
+	return duration.MakeDuration(durNanos, durDays, durMonths)
+}

server/functions/binary/divide.go

@@ -20,6 +20,7 @@ import (
 	"github.com/dolthub/go-mysql-server/sql"
 	"github.com/shopspring/decimal"
 
+	"github.com/dolthub/doltgresql/postgres/parser/duration"
 	"github.com/dolthub/doltgresql/server/functions/framework"
 	pgtypes "github.com/dolthub/doltgresql/server/types"
 )
@@ -42,6 +43,7 @@ func initBinaryDivide() {
 	framework.RegisterBinaryFunction(framework.Operator_BinaryDivide, int8div)
 	framework.RegisterBinaryFunction(framework.Operator_BinaryDivide, int82div)
 	framework.RegisterBinaryFunction(framework.Operator_BinaryDivide, int84div)
+	framework.RegisterBinaryFunction(framework.Operator_BinaryDivide, interval_div)
 	framework.RegisterBinaryFunction(framework.Operator_BinaryDivide, numeric_div)
 }
 
@@ -227,6 +229,20 @@ var int84div = framework.Function2{
 	},
 }
 
+// interval_div represents the PostgreSQL function of the same name, taking the same parameters.
+var interval_div = framework.Function2{
+	Name:       "interval_div",
+	Return:     pgtypes.Interval,
+	Parameters: [2]pgtypes.DoltgresType{pgtypes.Interval, pgtypes.Float64},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, _ [3]pgtypes.DoltgresType, val1 any, val2 any) (any, error) {
+		if val2.(float64) == 0 {
+			return nil, fmt.Errorf("division by zero")
+		}
+		return val1.(duration.Duration).DivFloat(val2.(float64)), nil
+	},
+}
+
 // numeric_div represents the PostgreSQL function of the same name, taking the same parameters.
 var numeric_div = framework.Function2{
 	Name:       "numeric_div",

server/functions/binary/equal.go

@@ -20,6 +20,7 @@ import (
 	"github.com/dolthub/go-mysql-server/sql"
 	"github.com/shopspring/decimal"
 
+	"github.com/dolthub/doltgresql/postgres/parser/duration"
 	"github.com/dolthub/doltgresql/postgres/parser/uuid"
 	"github.com/dolthub/doltgresql/server/functions/framework"
 	pgtypes "github.com/dolthub/doltgresql/server/types"
@@ -50,6 +51,7 @@ func initBinaryEqual() {
 	framework.RegisterBinaryFunction(framework.Operator_BinaryEqual, int82eq)
 	framework.RegisterBinaryFunction(framework.Operator_BinaryEqual, int84eq)
 	framework.RegisterBinaryFunction(framework.Operator_BinaryEqual, int8eq)
+	framework.RegisterBinaryFunction(framework.Operator_BinaryEqual, interval_eq)
 	framework.RegisterBinaryFunction(framework.Operator_BinaryEqual, jsonb_eq)
 	framework.RegisterBinaryFunction(framework.Operator_BinaryEqual, nameeq)
 	framework.RegisterBinaryFunction(framework.Operator_BinaryEqual, nameeqtext)
@@ -310,6 +312,18 @@ var int8eq = framework.Function2{
 	},
 }
 
+// interval_eq represents the PostgreSQL function of the same name, taking the same parameters.
+var interval_eq = framework.Function2{
+	Name:       "interval_eq",
+	Return:     pgtypes.Bool,
+	Parameters: [2]pgtypes.DoltgresType{pgtypes.Interval, pgtypes.Interval},
+	Strict:     true,
+	Callable: func(ctx *sql.Context, _ [3]pgtypes.DoltgresType, val1 any, val2 any) (any, error) {
+		res, err := pgtypes.Interval.Compare(val1.(duration.Duration), val2.(duration.Duration))
+		return res == 0, err
+	},
+}
+
 // jsonb_eq represents the PostgreSQL function of the same name, taking the same parameters.
 var jsonb_eq = framework.Function2{
 	Name:       "jsonb_eq",