diff --git a/src/Db/Adapter/MysqlAdapter.php b/src/Db/Adapter/MysqlAdapter.php
index 01dfe8c1..694f821b 100644
--- a/src/Db/Adapter/MysqlAdapter.php
+++ b/src/Db/Adapter/MysqlAdapter.php
@@ -29,6 +29,11 @@
  */
 class MysqlAdapter extends AbstractAdapter
 {
+    /**
+     * Maximum length for identifiers (table names, column names, constraint names, etc.)
+     */
+    protected const IDENTIFIER_MAX_LENGTH = 64;
+
     /**
      * @var string[]
      */
@@ -1197,7 +1202,7 @@ protected function getIndexSqlDefinition(Index $index): string
      */
     protected function getForeignKeySqlDefinition(ForeignKey $foreignKey, string $tableName): string
     {
-        $constraintName = $foreignKey->getName() ?: ($tableName . '_' . implode('_', $foreignKey->getColumns()));
+        $constraintName = $foreignKey->getName() ?: $this->getUniqueForeignKeyName($tableName, $foreignKey->getColumns());
         $def = ' CONSTRAINT ' . $this->quoteColumnName($constraintName);
         $columnNames = [];
         foreach ($foreignKey->getColumns() as $column) {
@@ -1221,6 +1226,35 @@ protected function getForeignKeySqlDefinition(ForeignKey $foreignKey, string $ta
         return $def;
     }
 
+    /**
+     * Generate a unique foreign key constraint name.
+     *
+     * @param string $tableName Table name
+     * @param array<string> $columns Column names
+     * @return string
+     */
+    protected function getUniqueForeignKeyName(string $tableName, array $columns): string
+    {
+        $baseName = $tableName . '_' . implode('_', $columns);
+        $maxLength = static::IDENTIFIER_MAX_LENGTH - 3;
+        if (strlen($baseName) > $maxLength) {
+            $baseName = substr($baseName, 0, $maxLength);
+        }
+        $existingKeys = $this->getForeignKeys($tableName);
+        $existingNames = array_column($existingKeys, 'name');
+
+        if (!in_array($baseName, $existingNames, true)) {
+            return $baseName;
+        }
+
+        $counter = 2;
+        while (in_array($baseName . '_' . $counter, $existingNames, true)) {
+            $counter++;
+        }
+
+        return $baseName . '_' . $counter;
+    }
+
     /**
      * Returns MySQL column types (inherited and MySQL specified).
      *
diff --git a/src/Db/Adapter/PostgresAdapter.php b/src/Db/Adapter/PostgresAdapter.php
index 878f81ee..b0e61d22 100644
--- a/src/Db/Adapter/PostgresAdapter.php
+++ b/src/Db/Adapter/PostgresAdapter.php
@@ -27,6 +27,11 @@
 
 class PostgresAdapter extends AbstractAdapter
 {
+    /**
+     * Maximum length for identifiers (table names, column names, constraint names, etc.)
+     */
+    protected const IDENTIFIER_MAX_LENGTH = 63;
+
     public const GENERATED_ALWAYS = 'ALWAYS';
     public const GENERATED_BY_DEFAULT = 'BY DEFAULT';
     /**
@@ -949,11 +954,7 @@ protected function getIndexSqlDefinition(Index $index, string $tableName): strin
      */
     protected function getForeignKeySqlDefinition(ForeignKey $foreignKey, string $tableName): string
     {
-        $parts = $this->getSchemaName($tableName);
-
-        $constraintName = $foreignKey->getName() ?: (
-            $parts['table'] . '_' . implode('_', $foreignKey->getColumns()) . '_fkey'
-        );
+        $constraintName = $foreignKey->getName() ?: $this->getUniqueForeignKeyName($tableName, $foreignKey->getColumns());
         $columnList = implode(', ', array_map($this->quoteColumnName(...), $foreignKey->getColumns()));
         $refColumnList = implode(', ', array_map($this->quoteColumnName(...), $foreignKey->getReferencedColumns()));
         $def = ' CONSTRAINT ' . $this->quoteColumnName($constraintName) .
@@ -972,6 +973,36 @@ protected function getForeignKeySqlDefinition(ForeignKey $foreignKey, string $ta
         return $def;
     }
 
+    /**
+     * Generate a unique foreign key constraint name.
+     *
+     * @param string $tableName Table name
+     * @param array<string> $columns Column names
+     * @return string
+     */
+    protected function getUniqueForeignKeyName(string $tableName, array $columns): string
+    {
+        $parts = $this->getSchemaName($tableName);
+        $baseName = $parts['table'] . '_' . implode('_', $columns) . '_fkey';
+        $maxLength = static::IDENTIFIER_MAX_LENGTH - 3;
+        if (strlen($baseName) > $maxLength) {
+            $baseName = substr($baseName, 0, $maxLength);
+        }
+        $existingKeys = $this->getForeignKeys($tableName);
+        $existingNames = array_column($existingKeys, 'name');
+
+        if (!in_array($baseName, $existingNames, true)) {
+            return $baseName;
+        }
+
+        $counter = 2;
+        while (in_array($baseName . '_' . $counter, $existingNames, true)) {
+            $counter++;
+        }
+
+        return $baseName . '_' . $counter;
+    }
+
     /**
      * @inheritDoc
      */
diff --git a/src/Db/Adapter/SqliteAdapter.php b/src/Db/Adapter/SqliteAdapter.php
index f78ff76b..82a3812d 100644
--- a/src/Db/Adapter/SqliteAdapter.php
+++ b/src/Db/Adapter/SqliteAdapter.php
@@ -1675,7 +1675,7 @@ public function getColumnTypes(): array
      */
     protected function getForeignKeySqlDefinition(ForeignKey $foreignKey, string $tableName): string
     {
-        $constraintName = $foreignKey->getName() ?: ($tableName . '_' . implode('_', $foreignKey->getColumns()));
+        $constraintName = $foreignKey->getName() ?: $this->getUniqueForeignKeyName($tableName, $foreignKey->getColumns());
         $def = ' CONSTRAINT ' . $this->quoteColumnName($constraintName);
         $columnNames = [];
         foreach ($foreignKey->getColumns() as $column) {
@@ -1697,6 +1697,31 @@ protected function getForeignKeySqlDefinition(ForeignKey $foreignKey, string $ta
         return $def;
     }
 
+    /**
+     * Generate a unique foreign key constraint name.
+     *
+     * @param string $tableName Table name
+     * @param array<string> $columns Column names
+     * @return string
+     */
+    protected function getUniqueForeignKeyName(string $tableName, array $columns): string
+    {
+        $baseName = $tableName . '_' . implode('_', $columns);
+        $existingKeys = $this->getForeignKeys($tableName);
+        $existingNames = array_column($existingKeys, 'name');
+
+        if (!in_array($baseName, $existingNames, true)) {
+            return $baseName;
+        }
+
+        $counter = 2;
+        while (in_array($baseName . '_' . $counter, $existingNames, true)) {
+            $counter++;
+        }
+
+        return $baseName . '_' . $counter;
+    }
+
     /**
      * @inheritDoc
      */
diff --git a/src/Db/Adapter/SqlserverAdapter.php b/src/Db/Adapter/SqlserverAdapter.php
index e804d590..67f08c00 100644
--- a/src/Db/Adapter/SqlserverAdapter.php
+++ b/src/Db/Adapter/SqlserverAdapter.php
@@ -28,6 +28,11 @@
  */
 class SqlserverAdapter extends AbstractAdapter
 {
+    /**
+     * Maximum length for identifiers (table names, column names, constraint names, etc.)
+     */
+    protected const IDENTIFIER_MAX_LENGTH = 128;
+
     /**
      * @var string[]
      */
@@ -864,7 +869,7 @@ protected function getIndexSqlDefinition(Index $index, string $tableName): strin
      */
     protected function getForeignKeySqlDefinition(ForeignKey $foreignKey, string $tableName): string
     {
-        $constraintName = $foreignKey->getName() ?: $tableName . '_' . implode('_', $foreignKey->getColumns());
+        $constraintName = $foreignKey->getName() ?: $this->getUniqueForeignKeyName($tableName, $foreignKey->getColumns());
         $columnList = implode(', ', array_map($this->quoteColumnName(...), $foreignKey->getColumns()));
         $refColumnList = implode(', ', array_map($this->quoteColumnName(...), $foreignKey->getReferencedColumns()));
 
@@ -881,6 +886,35 @@ protected function getForeignKeySqlDefinition(ForeignKey $foreignKey, string $ta
         return $def;
     }
 
+    /**
+     * Generate a unique foreign key constraint name.
+     *
+     * @param string $tableName Table name
+     * @param array<string> $columns Column names
+     * @return string
+     */
+    protected function getUniqueForeignKeyName(string $tableName, array $columns): string
+    {
+        $baseName = $tableName . '_' . implode('_', $columns);
+        $maxLength = static::IDENTIFIER_MAX_LENGTH - 3;
+        if (strlen($baseName) > $maxLength) {
+            $baseName = substr($baseName, 0, $maxLength);
+        }
+        $existingKeys = $this->getForeignKeys($tableName);
+        $existingNames = array_column($existingKeys, 'name');
+
+        if (!in_array($baseName, $existingNames, true)) {
+            return $baseName;
+        }
+
+        $counter = 2;
+        while (in_array($baseName . '_' . $counter, $existingNames, true)) {
+            $counter++;
+        }
+
+        return $baseName . '_' . $counter;
+    }
+
     /**
      * Creates the specified schema.
      *