Implement SELECT for simple SQLite queries (#360)

* Lemon select

* sqlite: Translate select stmts

* endtoend: Use a single SQL file for experimental

Author: kyleconroy

internal/endtoend/testdata/experimental.sql

@@ -0,0 +1,12 @@
+CREATE TABLE foo (
+        bar text NOT NULL 
+);
+
+CREATE TABLE bar (
+        baz text NOT NULL 
+);
+
+SELECT bar FROM foo;
+
+DROP TABLE bar;
+DROP TABLE IF EXISTS baz;

internal/endtoend/testdata/experimental_dolphin/query.sql

@@ -5,8 +5,8 @@
       "path": "go",
       "name": "querytest",
       "engine": "_dolphin",
-      "schema": "query.sql",
-      "queries": "query.sql"
+      "schema": "../experimental.sql",
+      "queries": "../experimental.sql"
     }
   ]
 }

internal/endtoend/testdata/experimental_dolphin/sqlc.json

@@ -5,8 +5,8 @@
       "path": "go",
       "name": "querytest",
       "engine": "_elephant",
-      "schema": "query.sql",
-      "queries": "query.sql"
+      "schema": "../experimental.sql",
+      "queries": "../experimental.sql"
     }
   ]
 }

internal/endtoend/testdata/experimental_elephant/query.sql

@@ -5,8 +5,8 @@
       "path": "go",
       "name": "querytest",
       "engine": "_lemon",
-      "schema": "query.sql",
-      "queries": "query.sql"
+      "schema": "../experimental.sql",
+      "queries": "../experimental.sql"
     }
   ]
 }

internal/endtoend/testdata/experimental_elephant/sqlc.json

@@ -0,0 +1,141 @@
+package sqlite
+
+import (
+	"github.com/kyleconroy/sqlc/internal/sql/ast"
+	"github.com/kyleconroy/sqlc/internal/sqlite/parser"
+)
+
+type listener struct {
+	*parser.BaseSQLiteListener
+
+	stmt *ast.RawStmt
+
+	stmts []ast.Statement
+}
+
+// The Visitor code generated by Antlr doesn't currently work
+//
+// To make due, we mark the listener as "busy" if it's currently processing a
+// node. This helps avoids scenarios where enter is called on nested
+// statements.
+func (l *listener) busy() bool {
+	return l.stmt != nil
+}
+
+func (l *listener) EnterSql_stmt(c *parser.Sql_stmtContext) {
+	l.stmt = nil
+}
+
+func (l *listener) ExitSql_stmt(c *parser.Sql_stmtContext) {
+	if l.stmt != nil {
+		l.stmts = append(l.stmts, ast.Statement{
+			Raw: l.stmt,
+		})
+	}
+}
+
+func (l *listener) EnterCreate_table_stmt(c *parser.Create_table_stmtContext) {
+	if l.busy() {
+		return
+	}
+
+	name := ast.TableName{
+		Name: c.Table_name().GetText(),
+	}
+
+	if c.Database_name() != nil {
+		name.Schema = c.Database_name().GetText()
+	}
+
+	stmt := &ast.CreateTableStmt{
+		Name:        &name,
+		IfNotExists: c.K_EXISTS() != nil,
+	}
+
+	for _, idef := range c.AllColumn_def() {
+		if def, ok := idef.(*parser.Column_defContext); ok {
+			stmt.Cols = append(stmt.Cols, &ast.ColumnDef{
+				Colname: def.Column_name().GetText(),
+				TypeName: &ast.TypeName{
+					Name: def.Type_name().GetText(),
+				},
+			})
+		}
+	}
+
+	l.stmt = &ast.RawStmt{Stmt: stmt}
+}
+
+func (l *listener) EnterDrop_table_stmt(c *parser.Drop_table_stmtContext) {
+	if l.busy() {
+		return
+	}
+
+	drop := &ast.DropTableStmt{
+		IfExists: c.K_EXISTS() != nil,
+	}
+
+	name := ast.TableName{
+		Name: c.Table_name().GetText(),
+	}
+
+	if c.Database_name() != nil {
+		name.Schema = c.Database_name().GetText()
+	}
+
+	drop.Tables = append(drop.Tables, &name)
+	l.stmt = &ast.RawStmt{Stmt: drop}
+}
+
+func (l *listener) EnterFactored_select_stmt(c *parser.Factored_select_stmtContext) {
+	if l.busy() {
+		return
+	}
+
+	var tables []ast.Node
+	var cols []ast.Node
+	for _, icore := range c.AllSelect_core() {
+		core, ok := icore.(*parser.Select_coreContext)
+		if !ok {
+			continue
+		}
+		for _, icol := range core.AllResult_column() {
+			col, ok := icol.(*parser.Result_columnContext)
+			if !ok {
+				continue
+			}
+			iexpr := col.Expr()
+			if iexpr == nil {
+				continue
+			}
+			expr, ok := iexpr.(*parser.ExprContext)
+			if !ok {
+				continue
+			}
+			cols = append(cols, &ast.ResTarget{
+				Val: &ast.ColumnRef{
+					Name: expr.Column_name().GetText(),
+				},
+			})
+		}
+		for _, ifrom := range core.AllTable_or_subquery() {
+			from, ok := ifrom.(*parser.Table_or_subqueryContext)
+			if !ok {
+				continue
+			}
+			name := ast.TableName{
+				Name: from.Table_name().GetText(),
+			}
+			if from.Schema_name() != nil {
+				name.Schema = from.Schema_name().GetText()
+			}
+			tables = append(tables, &name)
+		}
+	}
+
+	sel := &ast.SelectStmt{
+		From:   &ast.List{Items: tables},
+		Fields: &ast.List{Items: cols},
+	}
+	l.stmt = &ast.RawStmt{Stmt: sel}
+}

internal/endtoend/testdata/experimental_lemon/query.sql

@@ -11,55 +11,6 @@ import (
 	"github.com/kyleconroy/sqlc/internal/sqlite/parser"
 )
 
-type listener struct {
-	*parser.BaseSQLiteListener
-
-	stmt *ast.RawStmt
-
-	stmts []ast.Statement
-}
-
-func (l *listener) EnterSql_stmt(c *parser.Sql_stmtContext) {
-	l.stmt = nil
-}
-
-func (l *listener) ExitSql_stmt(c *parser.Sql_stmtContext) {
-	if l.stmt != nil {
-		l.stmts = append(l.stmts, ast.Statement{
-			Raw: l.stmt,
-		})
-		return
-	}
-}
-
-func (l *listener) EnterCreate_table_stmt(c *parser.Create_table_stmtContext) {
-	name := ast.TableName{
-		Name: c.Table_name().GetText(),
-	}
-
-	if c.Database_name() != nil {
-		name.Schema = c.Database_name().GetText()
-	}
-
-	stmt := &ast.CreateTableStmt{
-		Name:        &name,
-		IfNotExists: c.K_EXISTS() != nil,
-	}
-
-	for _, idef := range c.AllColumn_def() {
-		if def, ok := idef.(*parser.Column_defContext); ok {
-			stmt.Cols = append(stmt.Cols, &ast.ColumnDef{
-				Colname: def.Column_name().GetText(),
-				TypeName: &ast.TypeName{
-					Name: def.Type_name().GetText(),
-				},
-			})
-		}
-	}
-
-	l.stmt = &ast.RawStmt{Stmt: stmt}
-}
-
 type errorListener struct {
 	*antlr.DefaultErrorListener
 
@@ -98,11 +49,11 @@ func (p *Parser) Parse(r io.Reader) ([]ast.Statement, error) {
 	l := &listener{}
 	el := &errorListener{}
 	pp.AddErrorListener(el)
+	// pp.BuildParseTrees = true
 	tree := pp.Parse()
 	if el.err != "" {
 		return nil, errors.New(el.err)
 	}
-	// p.BuildParseTrees = true
 	antlr.ParseTreeWalkerDefault.Walk(l, tree)
 	return l.stmts, nil
 }