[doc] updated url links in documentation (apache#4679)

docs/content/flink/sql-write.md

@@ -176,8 +176,8 @@ PARTITION (k0 = 0, k1 = 0) SELECT v FROM my_table WHERE false;
 {{< hint info >}}
 Important table properties setting:
 1. Only [primary key table]({{< ref "primary-key-table/overview" >}}) supports this feature.
-2. [MergeEngine]({{< ref "primary-key-table/merge-engine" >}}) needs to be [deduplicate]({{< ref "primary-key-table/merge-engine#deduplicate" >}})
-   or [partial-update]({{< ref "primary-key-table/merge-engine#partial-update" >}}) to support this feature.
+2. [MergeEngine]({{< ref "primary-key-table/merge-engine" >}}) needs to be [deduplicate]({{< ref "primary-key-table/merge-engine/overview/#deduplicate" >}})
+   or [partial-update]({{< ref "primary-key-table/merge-engine/partial-update/" >}}) to support this feature.
 3. Do not support updating primary keys.
 {{< /hint >}}
 
@@ -211,9 +211,9 @@ UPDATE my_table SET b = 1, c = 2 WHERE a = 'myTable';
 {{< hint info >}}
 Important table properties setting:
 1. Only primary key tables support this feature.
-2. If the table has primary keys, the following [MergeEngine]({{< ref "primary-key-table/merge-engine" >}}) support this feature:
-   * [deduplicate]({{< ref "primary-key-table/merge-engine#deduplicate" >}}).
-   * [partial-update]({{< ref "primary-key-table/merge-engine#partial-update" >}}) with option 'partial-update.remove-record-on-delete' enabled.
+2. If the table has primary keys, the following [MergeEngine]({{< ref "primary-key-table/merge-engine/overview/" >}}) support this feature:
+   * [deduplicate]({{< ref "primary-key-table/merge-engine/overview/#deduplicate" >}}).
+   * [partial-update]({{< ref "primary-key-table/merge-engine/partial-update/" >}}) with option 'partial-update.remove-record-on-delete' enabled.
 3. Do not support deleting from table in streaming mode.
 {{< /hint >}}