lab 05

labs/05/server2/modules/SqlStatement.js

@@ -0,0 +1,35 @@
+const SELECT_PATTERN = /^select\b/i;
+const INSERT_PATTERN = /^insert\b/i;
+
+export class SqlStatement {
+  constructor(text) {
+    // a trailing semicolon is harmless, it only makes the url uglier
+    this.text = String(text ?? "").trim().replace(/;+$/, "").trim();
+  }
+
+  isEmpty() {
+    return this.text.length === 0;
+  }
+
+  isSelect() {
+    return SELECT_PATTERN.test(this.text);
+  }
+
+  isInsert() {
+    return INSERT_PATTERN.test(this.text);
+  }
+
+  // a semicolon inside a quoted literal is data, not a second statement,
+  // so blank the literals out before looking for one.
+  isSingleStatement() {
+    const withoutLiterals = this.text
+      .replace(/'(?:[^']|'')*'/g, "''")
+      .replace(/"(?:[^"]|"")*"/g, '""');
+
+    return !withoutLiterals.includes(";");
+  }
+
+  toString() {
+    return this.text;
+  }
+}