From 47272104fe59162dfb157b3825ab193c62bdb448 Mon Sep 17 00:00:00 2001
From: Jan Was <jan.was@starburstdata.com>
Date: Sun, 10 Jul 2022 18:05:22 +0200
Subject: [PATCH] Support passing slices as query args

---
 README.md                 | 25 +++++++++++++++++++++++-
 trino/integration_test.go | 41 +++++++++++++++++++++++++++++++++++++++
 trino/trino.go            | 15 +++++++++++---
 3 files changed, 77 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index b289da0..0706547 100644
--- a/README.md
+++ b/README.md
@@ -190,7 +190,30 @@ https://user@localhost:8443?session_properties=query_max_run_time=10m,query_prio
 
 ## Data types
 
-The driver supports most Trino data types, except:
+### Query arguments
+
+When passing arguments to queries, the driver supports the following Go data types:
+* integers
+* `bool`
+* `string`
+* slices
+
+It's not yet possible to pass:
+* `nil`
+* `float32` or `float64`
+* `byte`
+* `time.Time` or `time.Duration`
+* `json.RawMessage`
+* maps
+
+To use the unsupported types, pass them as strings and use casts in the query, like so:
+```sql
+SELECT * FROM table WHERE col_double = cast(? AS DOUBLE) OR col_timestamp = CAST(? AS TIMESTAMP)
+```
+
+### Response rows
+
+When reading response rows, the driver supports most Trino data types, except:
 * time and timestamps with precision - all time types are returned as `time.Time`
 * `DECIMAL` - returned as string
 * `IPADDRESS` - returned as string
diff --git a/trino/integration_test.go b/trino/integration_test.go
index c986078..506b72b 100644
--- a/trino/integration_test.go
+++ b/trino/integration_test.go
@@ -391,6 +391,47 @@ func TestIntegrationTypeConversion(t *testing.T) {
 	}
 }
 
+func TestIntegrationArgsConversion(t *testing.T) {
+	dsn := *integrationServerFlag
+	dsn += "?session_properties=parse_decimal_literals_as_double=true"
+	db := integrationOpen(t, dsn)
+	value := 0
+	err := db.QueryRow(`
+		SELECT 1 FROM (VALUES (
+			CAST(1 AS TINYINT),
+			CAST(1 AS SMALLINT),
+			CAST(1 AS INTEGER),
+			CAST(1 AS BIGINT),
+			CAST(1 AS REAL),
+			CAST(1 AS DOUBLE),
+			TIMESTAMP '2017-07-10 01:02:03.004 UTC',
+			CAST('string' AS VARCHAR),
+			ARRAY['A', 'B']
+			)) AS t(col_tiny, col_small, col_int, col_big, col_real, col_double, col_ts, col_varchar, col_array )
+			WHERE 1=1
+			AND col_tiny = ?
+			AND col_small = ?
+			AND col_int = ?
+			AND col_big = ?
+			AND col_real = cast(? as real)
+			AND col_double = cast(? as double)
+			AND col_ts = cast(? as timestamp)
+			AND col_varchar = ?
+			AND col_array = ?`,
+		int16(1),
+		int16(1),
+		int32(1),
+		int64(1),
+		Numeric("1"),
+		Numeric("1"),
+		"2017-07-10 01:02:03.004 UTC",
+		"string",
+		[]string{"A", "B"}).Scan(&value)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestIntegrationNoResults(t *testing.T) {
 	db := integrationOpen(t)
 	rows, err := db.Query("SELECT 1 LIMIT 0")
diff --git a/trino/trino.go b/trino/trino.go
index 99bc513..936d753 100644
--- a/trino/trino.go
+++ b/trino/trino.go
@@ -65,6 +65,7 @@ import (
 	"math"
 	"net/http"
 	"net/url"
+	"reflect"
 	"regexp"
 	"sort"
 	"strconv"
@@ -544,9 +545,10 @@ type driverStmt struct {
 }
 
 var (
-	_ driver.Stmt             = &driverStmt{}
-	_ driver.StmtQueryContext = &driverStmt{}
-	_ driver.StmtExecContext  = &driverStmt{}
+	_ driver.Stmt              = &driverStmt{}
+	_ driver.StmtQueryContext  = &driverStmt{}
+	_ driver.StmtExecContext   = &driverStmt{}
+	_ driver.NamedValueChecker = &driverStmt{}
 )
 
 func (st *driverStmt) Close() error {
@@ -583,6 +585,13 @@ func (st *driverStmt) ExecContext(ctx context.Context, args []driver.NamedValue)
 	return rows, nil
 }
 
+func (st *driverStmt) CheckNamedValue(arg *driver.NamedValue) error {
+	if reflect.TypeOf(arg.Value).Kind() == reflect.Slice {
+		return nil
+	}
+	return driver.ErrSkip
+}
+
 type stmtResponse struct {
 	ID          string    `json:"id"`
 	InfoURI     string    `json:"infoUri"`