Merge pull request #10 from bippio/examples

added example to enumerate DBs in Impala

examples/enumerateDB.go

@@ -0,0 +1,81 @@
+package main
+
+// Simple program to list databases and the tables
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	impala "github.com/bippio/go-impala"
+)
+
+func main() {
+	host := "<impala host>"
+	port := 21000
+
+	opts := impala.DefaultOptions
+
+	// enable LDAP authentication:
+	opts.UseLDAP = true
+	opts.Username = "<ldap username>"
+	opts.Password = "<ldap password>"
+
+	// enable TLS
+	opts.UseTLS = true
+	opts.CACertPath = "/path/to/cacert"
+
+	con, err := impala.Connect(host, port, &opts)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	ctx := context.Background()
+
+	var rows impala.RowSet
+
+	// get all databases for the connection object
+	query := fmt.Sprintf("SHOW DATABASES")
+	rows, err = con.Query(ctx, query)
+	if err != nil {
+		log.Fatal("error in retrieving databases: ", err)
+	}
+
+	databases := make([]string, 0) // databases will contain all the DBs to enumerate later
+	for rows.Next(ctx) {
+		row := make(map[string]interface{})
+		err = rows.MapScan(row)
+		if err != nil {
+			log.Println(err)
+			continue
+		}
+		if db, ok := row["name"].(string); ok {
+			databases = append(databases, db)
+		}
+	}
+	log.Println("List of Databases", databases)
+
+	for _, d := range databases {
+		q := "SHOW TABLES IN " + d
+
+		rows, err = con.Query(ctx, q)
+		if err != nil {
+			log.Printf("error in querying database %s: %s", d, err.Error())
+			continue
+		}
+
+		tables := make([]string, 0) // databases will contain all the DBs to enumerate later
+		for rows.Next(ctx) {
+			row := make(map[string]interface{})
+			err = rows.MapScan(row)
+			if err != nil {
+				log.Println(err)
+				continue
+			}
+			if tab, ok := row["name"].(string); ok {
+				tables = append(tables, tab)
+			}
+		}
+		log.Printf("List of Tables in Database %s: %v\n", d, tables)
+	}
+}