Simplify conditions

Author: mbaumgartl

lib/sql.js

@@ -163,15 +163,15 @@ function tablesToSQL(tables) {
     if (baseTable.type === 'dual') return 'DUAL';
     let str = baseTable.table ? identifierToSql(baseTable.table) : exprToSQL(baseTable.expr);
 
-    if (baseTable.db && baseTable.db !== null) str = baseTable.db + '.' + str;
+    if (baseTable.db) str = baseTable.db + '.' + str;
     if (baseTable.as !== null) str += ' AS ' + identifierToSql(baseTable.as);
 
     clauses.push(str);
 
     for (let i = 1; i < tables.length; i++) {
         const joinExpr = tables[i];
 
-        str = joinExpr.join && joinExpr.join !== null ? ' ' + joinExpr.join + ' ' : (str = ', ');
+        str = joinExpr.join ? ' ' + joinExpr.join + ' ' : (str = ', ');
 
         if (joinExpr.table) {
             if (joinExpr.db !== null) str += joinExpr.db + '.';
@@ -212,7 +212,7 @@ function withToSql(withExpr) {
  * @param {Object}          stmt
  * @param {?Array}          stmt.with
  * @param {?Array}          stmt.options
- * @param {?string}         stmt.distinct
+ * @param {string|null}     stmt.distinct
  * @param {?Array|string}   stmt.columns
  * @param {?Array}          stmt.from
  * @param {?Object}         stmt.where
@@ -229,8 +229,7 @@ function selectToSQL(stmt) {
     if (has(stmt, 'options') && Array.isArray(stmt.options)) clauses.push(stmt.options.join(' '));
     if (has(stmt, 'distinct') && stmt.distinct !== null) clauses.push(stmt.distinct);
 
-    if (stmt.columns !== '*') clauses.push(columnsToSQL(stmt.columns));
-    else clauses.push('*');
+    clauses.push(stmt.columns !== '*' ? columnsToSQL(stmt.columns) : '*');
 
     // FROM + joins
     if (Array.isArray(stmt.from)) clauses.push('FROM', tablesToSQL(stmt.from));