SNOW-988972 adding an example demonstrating how to insert data into VARIANT and OBJECT datatype columns with bind variables (snowflakedb#999)

* SNOW-988972 adding an example demonstrating how to insert data into VARIANT and OBJECT datatype columns with bind variables

* SNOW-988972 changes after first review

* SNOW-988972 changes
* minor reword of printing Create table
* adding unique table name
* printing query result type
* adding DROP after last query

* SNOW-988972 changes
* renaming directory to cmd/variant from cmd/insertvariantobject
* adding defer around the DROP TABLE statement

* SNOW-988972 changes
* using db.Conn + context to execute all queries in a single connection instead of connecting separately for each of them

Author: sfc-gh-dszmolka

cmd/variant/Makefile

@@ -0,0 +1,16 @@
+include ../../gosnowflake.mak
+CMD_TARGET=variant
+
+## Install
+install: cinstall
+
+## Run
+run: crun
+
+## Lint
+lint: clint
+
+## Format source codes
+fmt: cfmt
+
+.PHONY: install run lint fmt

cmd/variant/insertvariantobject.go

@@ -0,0 +1,117 @@
+package main
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
+	"strconv"
+	"time"
+
+	sf "github.com/snowflakedb/gosnowflake"
+)
+
+func main() {
+	if !flag.Parsed() {
+		flag.Parse()
+	}
+
+	cfg, err := sf.GetConfigFromEnv([]*sf.ConfigParam{
+		{Name: "Account", EnvName: "SNOWFLAKE_TEST_ACCOUNT", FailOnMissing: true},
+		{Name: "User", EnvName: "SNOWFLAKE_TEST_USER", FailOnMissing: true},
+		{Name: "Password", EnvName: "SNOWFLAKE_TEST_PASSWORD", FailOnMissing: true},
+		{Name: "Warehouse", EnvName: "SNOWFLAKE_TEST_WAREHOUSE", FailOnMissing: true},
+		{Name: "Database", EnvName: "SNOWFLAKE_TEST_DATABASE", FailOnMissing: true},
+		{Name: "Schema", EnvName: "SNOWFLAKE_TEST_SCHEMA", FailOnMissing: true},
+		{Name: "Host", EnvName: "SNOWFLAKE_TEST_HOST", FailOnMissing: false},
+		{Name: "Port", EnvName: "SNOWFLAKE_TEST_PORT", FailOnMissing: false},
+		{Name: "Protocol", EnvName: "SNOWFLAKE_TEST_PROTOCOL", FailOnMissing: false},
+	})
+	if err != nil {
+		log.Fatalf("failed to create Config, err: %v", err)
+	}
+	dsn, err := sf.DSN(cfg)
+	if err != nil {
+		log.Fatalf("failed to create DSN from Config: %v, err: %v", cfg, err)
+	}
+
+	db, err := sql.Open("snowflake", dsn)
+	if err != nil {
+		log.Fatalf("failed to connect. %v, err: %v", dsn, err)
+	}
+	defer db.Close()
+
+	ctx := context.Background()
+	conn, err := db.Conn(ctx)
+	if err != nil {
+		log.Fatalf("Failed to acquire connection. err: %v", err)
+	}
+	defer conn.Close()
+
+	tablename := "insert_variant_object_" + strconv.FormatInt(time.Now().UnixNano(), 10)
+	param := map[string]string{"key": "value"}
+	jsonStr, err := json.Marshal(param)
+	if err != nil {
+		log.Fatalf("failed to marshal json. err: %v", err)
+	}
+
+	createTableQuery := "CREATE TABLE " + tablename + " (c1 VARIANT, c2 OBJECT)"
+
+	// https://docs.snowflake.com/en/sql-reference/functions/parse_json
+	// can do with TO_VARIANT(PARSE_JSON(..)) as well, but PARSE_JSON already produces VARIANT
+	insertQuery := "INSERT INTO " + tablename + " (c1, c2) SELECT PARSE_JSON(?), TO_OBJECT(PARSE_JSON(?))"
+	// https://docs.snowflake.com/en/sql-reference/data-types-semistructured#object
+	insertOnlyObject := "INSERT INTO " + tablename + " (c2) SELECT OBJECT_CONSTRUCT('name', 'Jones'::VARIANT, 'age',  42::VARIANT)"
+
+	selectQuery := "SELECT c1, c2 FROM " + tablename
+
+	dropQuery := "DROP TABLE " + tablename
+
+	fmt.Printf("Creating table: %v\n", createTableQuery)
+	_, err = conn.ExecContext(ctx, createTableQuery)
+	if err != nil {
+		log.Fatalf("failed to run the query. %v, err: %v", createTableQuery, err)
+	}
+	defer func() {
+		fmt.Printf("Dropping the table: %v\n", dropQuery)
+		_, err = conn.ExecContext(ctx, dropQuery)
+		if err != nil {
+			log.Fatalf("failed to run the query. %v, err: %v", dropQuery, err)
+		}
+	}()
+	fmt.Printf("Inserting VARIANT and OBJECT data into table: %v\n", insertQuery)
+	_, err = conn.ExecContext(ctx, insertQuery,
+		string(jsonStr),
+		string(jsonStr),
+	)
+	if err != nil {
+		log.Fatalf("failed to run the query. %v, err: %v", insertQuery, err)
+	}
+	fmt.Printf("Now for another approach: %v\n", insertOnlyObject)
+	_, err = conn.ExecContext(ctx, insertOnlyObject)
+	if err != nil {
+		log.Fatalf("failed to run the query. %v, err: %v", insertOnlyObject, err)
+	}
+
+	fmt.Printf("Querying the table into which we just inserted the data: %v\n", selectQuery)
+	rows, err := conn.QueryContext(ctx, selectQuery)
+	if err != nil {
+		log.Fatalf("failed to run the query. %v, err: %v", selectQuery, err)
+	}
+	defer rows.Close()
+	var c1, c2 any
+	for rows.Next() {
+		err := rows.Scan(&c1, &c2)
+		if err != nil {
+			log.Fatalf("failed to get result. err: %v", err)
+		}
+		fmt.Printf("%v (type: %T), %v (type: %T)\n", c1, c1, c2, c2)
+	}
+	if rows.Err() != nil {
+		fmt.Printf("ERROR: %v\n", rows.Err())
+		return
+	}
+
+}