feat(print-statements): intercept explain query plan statements

Author: douglasmdev

Diff for: internal/db/output.go

@@ -21,7 +21,9 @@ type TablePrinter struct {
 func (t TablePrinter) print(statementResult StatementResult, outF io.Writer) error {
 	data := [][]string{}
 	table := createTable(outF)
-	if !t.withoutHeader {
+	showTableHeader := !t.withoutHeader &&
+		!IsResultComingFromExplainQueryPlan(statementResult)
+	if showTableHeader {
 		table.SetHeader(statementResult.ColumnNames)
 	}
 
@@ -98,7 +100,11 @@ func appendData(statementResult StatementResult, data [][]string, mode FormatTyp
 		if err != nil {
 			return [][]string{}, err
 		}
-		data = append(data, formattedRow)
+		if !IsResultComingFromExplainQueryPlan(statementResult) {
+			data = append(data, formattedRow)
+		} else {
+			data = append(data, []string{"Tree goes here!"})
+		}
 	}
 	return data, nil
 }

Diff for: internal/db/utils.go

@@ -4,6 +4,8 @@ import (
 	"net/url"
 	"strings"
 	"unicode"
+
+	"golang.org/x/exp/slices"
 )
 
 func IsUrl(uri string) bool {
@@ -45,3 +47,30 @@ func NeedsEscaping(name string) bool {
 	}
 	return false
 }
+
+var explainQueryPlanStatement = "EXPLAIN QUERY PLAN"
+var explainQueryPlanColumnNames = []string{"id", "parent", "notused", "detail"}
+
+func queryContainsExplainQueryPlanStatement(query string) bool {
+	return strings.Contains(query, explainQueryPlanStatement)
+}
+
+func columnNamesMatchExplainQueryPlan(colNames []string) bool {
+	if len(colNames) != len(explainQueryPlanColumnNames) {
+		return false
+	}
+	for _, colName := range explainQueryPlanColumnNames {
+		if !slices.Contains(colNames, colName) {
+			return false
+		}
+	}
+	return true
+}
+
+// "query" can be a string containing multiple queries separated by ";" or a single query
+func IsResultComingFromExplainQueryPlan(statementResult StatementResult) bool {
+	query := statementResult.Query
+	columnNames := statementResult.ColumnNames
+	return queryContainsExplainQueryPlanStatement(query) &&
+		columnNamesMatchExplainQueryPlan(columnNames)
+}