From 63847496f14c813a5d80efd5b7de0f1294ffe1e3 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 13 Apr 2024 16:07:11 +0200 Subject: Adding upstream version 3.45.1. Signed-off-by: Daniel Baumann --- www/session/sqlite3changeset_apply.html | 309 ++++++++++++++++++++++++++++++++ 1 file changed, 309 insertions(+) create mode 100644 www/session/sqlite3changeset_apply.html (limited to 'www/session/sqlite3changeset_apply.html') diff --git a/www/session/sqlite3changeset_apply.html b/www/session/sqlite3changeset_apply.html new file mode 100644 index 0000000..02849ff --- /dev/null +++ b/www/session/sqlite3changeset_apply.html @@ -0,0 +1,309 @@ + + + + + +Apply A Changeset To A Database + + + +
+ + + +
+
+Small. Fast. Reliable.
Choose any three. +
+
+ +
+ +
+
+ + + +
+
+
+ +

Session Module C Interface

Apply A Changeset To A Database

int sqlite3changeset_apply(
+  sqlite3 *db,                    /* Apply change to "main" db of this handle */
+  int nChangeset,                 /* Size of changeset in bytes */
+  void *pChangeset,               /* Changeset blob */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    const char *zTab              /* Table name */
+  ),
+  int(*xConflict)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
+    sqlite3_changeset_iter *p     /* Handle describing change and conflict */
+  ),
+  void *pCtx                      /* First argument passed to xConflict */
+);
+int sqlite3changeset_apply_v2(
+  sqlite3 *db,                    /* Apply change to "main" db of this handle */
+  int nChangeset,                 /* Size of changeset in bytes */
+  void *pChangeset,               /* Changeset blob */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    const char *zTab              /* Table name */
+  ),
+  int(*xConflict)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
+    sqlite3_changeset_iter *p     /* Handle describing change and conflict */
+  ),
+  void *pCtx,                     /* First argument passed to xConflict */
+  void **ppRebase, int *pnRebase, /* OUT: Rebase data */
+  int flags                       /* SESSION_CHANGESETAPPLY_* flags */
+);
+

+Apply a changeset or patchset to a database. These functions attempt to +update the "main" database attached to handle db with the changes found in +the changeset passed via the second and third arguments.

+ +

The fourth argument (xFilter) passed to these functions is the "filter +callback". If it is not NULL, then for each table affected by at least one +change in the changeset, the filter callback is invoked with +the table name as the second argument, and a copy of the context pointer +passed as the sixth argument as the first. If the "filter callback" +returns zero, then no attempt is made to apply any changes to the table. +Otherwise, if the return value is non-zero or the xFilter argument to +is NULL, all changes related to the table are attempted.

+ +

For each table that is not excluded by the filter callback, this function +tests that the target database contains a compatible table. A table is +considered compatible if all of the following are true:

+ +

+ +

If there is no compatible table, it is not an error, but none of the +changes associated with the table are applied. A warning message is issued +via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most +one such warning is issued for each table in the changeset.

+ +

For each change for which there is a compatible table, an attempt is made +to modify the table contents according to the UPDATE, INSERT or DELETE +change. If a change cannot be applied cleanly, the conflict handler +function passed as the fifth argument to sqlite3changeset_apply() may be +invoked. A description of exactly when the conflict handler is invoked for +each type of change is below.

+ +

Unlike the xFilter argument, xConflict may not be passed NULL. The results +of passing anything other than a valid function pointer as the xConflict +argument are undefined.

+ +

Each time the conflict handler function is invoked, it must return one +of SQLITE_CHANGESET_OMIT, SQLITE_CHANGESET_ABORT or +SQLITE_CHANGESET_REPLACE. SQLITE_CHANGESET_REPLACE may only be returned +if the second argument passed to the conflict handler is either +SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler +returns an illegal value, any changes already made are rolled back and +the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different +actions are taken by sqlite3changeset_apply() depending on the value +returned by each invocation of the conflict-handler function. Refer to +the documentation for the three +available return values for details.

+ +

+
DELETE Changes
+ For each DELETE change, the function checks if the target database + contains a row with the same primary key value (or values) as the + original row values stored in the changeset. If it does, and the values + stored in all non-primary key columns also match the values stored in + the changeset the row is deleted from the target database.

+ +

If a row with matching primary key values is found, but one or more of + the non-primary key fields contains a value different from the original + row value stored in the changeset, the conflict-handler function is + invoked with SQLITE_CHANGESET_DATA as the second argument. If the + database table has more columns than are recorded in the changeset, + only the values of those non-primary key fields are compared against + the current database contents - any trailing database table columns + are ignored.

+ +

If no row with matching primary key values is found in the database, + the conflict-handler function is invoked with SQLITE_CHANGESET_NOTFOUND + passed as the second argument.

+ +

If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT + (which can only happen if a foreign key constraint is violated), the + conflict-handler function is invoked with SQLITE_CHANGESET_CONSTRAINT + passed as the second argument. This includes the case where the DELETE + operation is attempted because an earlier call to the conflict handler + function returned SQLITE_CHANGESET_REPLACE.

+ +

INSERT Changes
+ For each INSERT change, an attempt is made to insert the new row into + the database. If the changeset row contains fewer fields than the + database table, the trailing fields are populated with their default + values.

+ +

If the attempt to insert the row fails because the database already + contains a row with the same primary key values, the conflict handler + function is invoked with the second argument set to + SQLITE_CHANGESET_CONFLICT.

+ +

If the attempt to insert the row fails because of some other constraint + violation (e.g. NOT NULL or UNIQUE), the conflict handler function is + invoked with the second argument set to SQLITE_CHANGESET_CONSTRAINT. + This includes the case where the INSERT operation is re-attempted because + an earlier call to the conflict handler function returned + SQLITE_CHANGESET_REPLACE.

+ +

UPDATE Changes
+ For each UPDATE change, the function checks if the target database + contains a row with the same primary key value (or values) as the + original row values stored in the changeset. If it does, and the values + stored in all modified non-primary key columns also match the values + stored in the changeset the row is updated within the target database.

+ +

If a row with matching primary key values is found, but one or more of + the modified non-primary key fields contains a value different from an + original row value stored in the changeset, the conflict-handler function + is invoked with SQLITE_CHANGESET_DATA as the second argument. Since + UPDATE changes only contain values for non-primary key fields that are + to be modified, only those fields need to match the original values to + avoid the SQLITE_CHANGESET_DATA conflict-handler callback.

+ +

If no row with matching primary key values is found in the database, + the conflict-handler function is invoked with SQLITE_CHANGESET_NOTFOUND + passed as the second argument.

+ +

If the UPDATE operation is attempted, but SQLite returns + SQLITE_CONSTRAINT, the conflict-handler function is invoked with + SQLITE_CHANGESET_CONSTRAINT passed as the second argument. + This includes the case where the UPDATE operation is attempted after + an earlier call to the conflict handler function returned + SQLITE_CHANGESET_REPLACE. +

+ +

It is safe to execute SQL statements, including those that write to the +table that the callback related to, from within the xConflict callback. +This can be used to further customize the application's conflict +resolution strategy.

+ +

All changes made by these functions are enclosed in a savepoint transaction. +If any other error (aside from a constraint failure when attempting to +write to the target database) occurs, then the savepoint transaction is +rolled back, restoring the target database to its original state, and an +SQLite error code returned.

+ +

If the output parameters (ppRebase) and (pnRebase) are non-NULL and +the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() +may set (*ppRebase) to point to a "rebase" that may be used with the +sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) +is set to the size of the buffer in bytes. It is the responsibility of the +caller to eventually free any such buffer using sqlite3_free(). The buffer +is only allocated and populated if one or more conflicts were encountered +while applying the patchset. See comments surrounding the sqlite3_rebaser +APIs for further details.

+ +

The behavior of sqlite3changeset_apply_v2() and its streaming equivalent +may be modified by passing a combination of +supported flags as the 9th parameter.

+ +

Note that the sqlite3changeset_apply_v2() API is still experimental +and therefore subject to change. +

See also lists of + Objects, + Constants, and + Functions.

+ -- cgit v1.2.3