Refactor search (#23550)

Co-Authored-By: Arve Knudsen <arve.knudsen@grafana.com>
Co-Authored-By: Leonard Gram <leonard.gram@grafana.com>

pkg/services/sqlstore/searchstore/builder.go

@@ -0,0 +1,112 @@
+package searchstore
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/grafana/grafana/pkg/services/sqlstore/migrator"
+	"strings"
+)
+
+// Builder defaults to returning a SQL query to get a list of all dashboards
+// in default order, but can be modified by applying filters.
+type Builder struct {
+	// List of FilterWhere/FilterGroupBy/FilterOrderBy/FilterLeftJoin
+	// to modify the query.
+	Filters []interface{}
+	Dialect migrator.Dialect
+
+	params []interface{}
+	sql    bytes.Buffer
+}
+
+// ToSql builds the SQL query and returns it as a string, together with the SQL parameters.
+func (b *Builder) ToSql(limit, page int64) (string, []interface{}) {
+	b.params = make([]interface{}, 0)
+	b.sql = bytes.Buffer{}
+
+	b.buildSelect()
+
+	b.sql.WriteString("( ")
+	b.applyFilters()
+
+	b.sql.WriteString(b.Dialect.LimitOffset(limit, (page-1)*limit) + `) AS ids
+		INNER JOIN dashboard ON ids.id = dashboard.id
+	`)
+
+	b.sql.WriteString(`
+		LEFT OUTER JOIN dashboard AS folder ON folder.id = dashboard.folder_id
+		LEFT OUTER JOIN dashboard_tag ON dashboard.id = dashboard_tag.dashboard_id`)
+
+	return b.sql.String(), b.params
+}
+
+func (b *Builder) buildSelect() {
+	b.sql.WriteString(
+		`SELECT
+			dashboard.id,
+			dashboard.uid,
+			dashboard.title,
+			dashboard.slug,
+			dashboard_tag.term,
+			dashboard.is_folder,
+			dashboard.folder_id,
+			folder.uid AS folder_uid,
+			folder.slug AS folder_slug,
+			folder.title AS folder_title
+		FROM `)
+}
+
+func (b *Builder) applyFilters() {
+	joins := []string{}
+
+	wheres := []string{}
+	whereParams := []interface{}{}
+
+	groups := []string{}
+	groupParams := []interface{}{}
+
+	orders := []string{}
+
+	for _, f := range b.Filters {
+		if f, ok := f.(FilterLeftJoin); ok {
+			joins = append(joins, fmt.Sprintf(" LEFT OUTER JOIN %s ", f.LeftJoin()))
+		}
+
+		if f, ok := f.(FilterWhere); ok {
+			sql, params := f.Where()
+			if sql != "" {
+				wheres = append(wheres, sql)
+				whereParams = append(whereParams, params...)
+			}
+		}
+
+		if f, ok := f.(FilterGroupBy); ok {
+			sql, params := f.GroupBy()
+			if sql != "" {
+				groups = append(groups, sql)
+				groupParams = append(groupParams, params...)
+			}
+		}
+
+		if f, ok := f.(FilterOrderBy); ok {
+			orders = append(orders, f.OrderBy())
+		}
+	}
+
+	b.sql.WriteString("SELECT dashboard.id FROM dashboard")
+	b.sql.WriteString(strings.Join(joins, ""))
+
+	if len(wheres) > 0 {
+		b.sql.WriteString(fmt.Sprintf(" WHERE %s", strings.Join(wheres, " AND ")))
+		b.params = append(b.params, whereParams...)
+	}
+
+	if len(groups) > 0 {
+		b.sql.WriteString(fmt.Sprintf(" GROUP BY %s", strings.Join(groups, ", ")))
+		b.params = append(b.params, groupParams...)
+	}
+
+	if len(orders) > 0 {
+		b.sql.WriteString(fmt.Sprintf(" ORDER BY %s", strings.Join(orders, ", ")))
+	}
+}