Fix subquery hover

Author: lighttiger2505

internal/handler/hover.go

@@ -169,6 +169,13 @@ func (e *hoverEnvironment) getSubQueryView(name string) (*parseutil.SubQueryInfo
 	return nil, false
 }
 
+func (e *hoverEnvironment) getSubQueryViewOne() (*parseutil.SubQueryInfo, bool) {
+	if len(e.subQueries) == 1 {
+		return e.subQueries[0], true
+	}
+	return nil, false
+}
+
 func (e *hoverEnvironment) isSubQuery(name string) bool {
 	_, ok := e.getSubQueryView(name)
 	return ok
@@ -246,6 +253,14 @@ func hoverContentFromIdent(ctx *hoverContext, identName string, dbCache *databas
 			return tableHoverInfo(tableName, cols)
 		}
 	}
+	if hoverTypeIs(ctx.types, hoverTypeSubQueryColumn) {
+		columnName := identName
+		subQueryView, ok := hoverEnv.getSubQueryViewOne()
+		if !ok {
+			return nil
+		}
+		return subqueryColumnHoverInfo(columnName, subQueryView, dbCache)
+	}
 	return nil
 }
 

internal/handler/hover_test.go

@@ -173,6 +173,20 @@ func TestHover(t *testing.T) {
 			line:   0,
 			col:    21,
 		},
+		{
+			name:   "select subquery ident parent head",
+			input:  "SELECT ID, Name FROM (SELECT ci.ID, ci.Name, ci.CountryCode, ci.District, ci.Population FROM city AS ci) as it",
+			output: "ID subquery column",
+			line:   0,
+			col:    8,
+		},
+		{
+			name:   "select subquery ident parent head",
+			input:  "SELECT ID, Name FROM (SELECT ci.ID, ci.Name, ci.CountryCode, ci.District, ci.Population FROM city AS ci) as it",
+			output: "Name subquery column",
+			line:   0,
+			col:    15,
+		},
 		{
 			name:   "select subquery member ident parent head",
 			input:  "SELECT it.ID, it.Name FROM (SELECT ci.ID, ci.Name, ci.CountryCode, ci.District, ci.Population FROM city AS ci) as it",