<!-- BEGIN: PAGE_EXTRA1 -->
<a href=https://www.cotonti.com/"{PAGE_EXTRA1}">НАША ССЫЛКА</a>
<!-- END: PAGE_EXTRA1 -->

<a href=https://www.cotonti.com/"{PAGE_EXTRA1}">НАША ССЫЛКА</a>

<a href=https://www.cotonti.com/"">НАША ССЫЛКА</a>

<!-- BEGIN: PAGE_EXTRA1 -->
<a href=https://www.cotonti.com/"{PAGE_EXTRA1}">НАША ССЫЛКА</a>
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CREATE TABLE example (
  id INT NOT NULL AUTO_INCREMENT,
  name VARCHAR(255) NOT NULL,
  PRIMARY KEY(id)
);

CREATE TABLE extras (
  id INT NOT NULL AUTO_INCREMENT,
  parent_table VARCHAR(100) NOT NULL,
  name VARCHAR(100) NOT NULL,
  PRIMARY KEY(id),
  KEY(parent_table)
);

CREATE TABLE extra_values (
  extra INT NOT NULL REFERENCES extras(id),
  value VARCHAR(255) NOT NULL,
  KEY(extra)
);