+++ /dev/null
-/*
-** 2008 October 10
-**
-** The author disclaims copyright to this source code. In place of
-** a legal notice, here is a blessing:
-**
-** May you do good and not evil.
-** May you find forgiveness for yourself and forgive others.
-** May you share freely, never taking more than you give.
-**
-*************************************************************************
-** This file contains C code for 'genfkey', a program to generate trigger
-** definitions that emulate foreign keys. See genfkey.README for details.
-**
-** $Id: genfkey.c,v 1.2 2008/10/13 10:56:48 danielk1977 Exp $
-*/
-
-#include "sqlite3.h"
-#include <stdio.h>
-#include <assert.h>
-#include <stdlib.h>
-#include <string.h>
-
-/**************************************************************************
-***************************************************************************
-** Start of virtual table implementations.
-**************************************************************************/
-
-/* The code in this file defines a sqlite3 virtual-table module that
-** provides a read-only view of the current database schema. There is one
-** row in the schema table for each column in the database schema.
-*/
-#define SCHEMA \
-"CREATE TABLE x(" \
- "database," /* Name of database (i.e. main, temp etc.) */ \
- "tablename," /* Name of table */ \
- "cid," /* Column number (from left-to-right, 0 upward) */ \
- "name," /* Column name */ \
- "type," /* Specified type (i.e. VARCHAR(32)) */ \
- "not_null," /* Boolean. True if NOT NULL was specified */ \
- "dflt_value," /* Default value for this column */ \
- "pk" /* True if this column is part of the primary key */ \
-")"
-
-#define SCHEMA2 \
-"CREATE TABLE x(" \
- "database," /* Name of database (i.e. main, temp etc.) */ \
- "from_tbl," /* Name of table */ \
- "fkid," \
- "seq," \
- "to_tbl," \
- "from_col," \
- "to_col," \
- "on_update," \
- "on_delete," \
- "match" \
-")"
-
-#define SCHEMA3 \
-"CREATE TABLE x(" \
- "database," /* Name of database (i.e. main, temp etc.) */ \
- "tablename," /* Name of table */ \
- "seq," \
- "name," \
- "isunique" \
-")"
-
-#define SCHEMA4 \
-"CREATE TABLE x(" \
- "database," /* Name of database (i.e. main, temp etc.) */ \
- "indexname," /* Name of table */ \
- "seqno," \
- "cid," \
- "name" \
-")"
-
-typedef struct SchemaTable SchemaTable;
-struct SchemaTable {
- const char *zName;
- const char *zObject;
- const char *zPragma;
- const char *zSchema;
-} aSchemaTable[] = {
- { "table_info", "table", "PRAGMA %Q.table_info(%Q)", SCHEMA },
- { "foreign_key_list", "table", "PRAGMA %Q.foreign_key_list(%Q)", SCHEMA2 },
- { "index_list", "table", "PRAGMA %Q.index_list(%Q)", SCHEMA3 },
- { "index_info", "index", "PRAGMA %Q.index_info(%Q)", SCHEMA4 },
- { 0, 0, 0, 0 }
-};
-
-typedef struct schema_vtab schema_vtab;
-typedef struct schema_cursor schema_cursor;
-
-/* A schema table object */
-struct schema_vtab {
- sqlite3_vtab base;
- sqlite3 *db;
- SchemaTable *pType;
-};
-
-/* A schema table cursor object */
-struct schema_cursor {
- sqlite3_vtab_cursor base;
- sqlite3_stmt *pDbList;
- sqlite3_stmt *pTableList;
- sqlite3_stmt *pColumnList;
- int rowid;
-};
-
-/*
-** Table destructor for the schema module.
-*/
-static int schemaDestroy(sqlite3_vtab *pVtab){
- sqlite3_free(pVtab);
- return 0;
-}
-
-/*
-** Table constructor for the schema module.
-*/
-static int schemaCreate(
- sqlite3 *db,
- void *pAux,
- int argc, const char *const*argv,
- sqlite3_vtab **ppVtab,
- char **pzErr
-){
- int rc = SQLITE_NOMEM;
- schema_vtab *pVtab;
- SchemaTable *pType = &aSchemaTable[0];
-
- if( argc>3 ){
- int i;
- pType = 0;
- for(i=0; aSchemaTable[i].zName; i++){
- if( 0==strcmp(argv[3], aSchemaTable[i].zName) ){
- pType = &aSchemaTable[i];
- }
- }
- if( !pType ){
- return SQLITE_ERROR;
- }
- }
-
- pVtab = sqlite3_malloc(sizeof(schema_vtab));
- if( pVtab ){
- memset(pVtab, 0, sizeof(schema_vtab));
- pVtab->db = db;
- pVtab->pType = pType;
- rc = sqlite3_declare_vtab(db, pType->zSchema);
- }
- *ppVtab = (sqlite3_vtab *)pVtab;
- return rc;
-}
-
-/*
-** Open a new cursor on the schema table.
-*/
-static int schemaOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
- int rc = SQLITE_NOMEM;
- schema_cursor *pCur;
- pCur = sqlite3_malloc(sizeof(schema_cursor));
- if( pCur ){
- memset(pCur, 0, sizeof(schema_cursor));
- *ppCursor = (sqlite3_vtab_cursor *)pCur;
- rc = SQLITE_OK;
- }
- return rc;
-}
-
-/*
-** Close a schema table cursor.
-*/
-static int schemaClose(sqlite3_vtab_cursor *cur){
- schema_cursor *pCur = (schema_cursor *)cur;
- sqlite3_finalize(pCur->pDbList);
- sqlite3_finalize(pCur->pTableList);
- sqlite3_finalize(pCur->pColumnList);
- sqlite3_free(pCur);
- return SQLITE_OK;
-}
-
-/*
-** Retrieve a column of data.
-*/
-static int schemaColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
- schema_cursor *pCur = (schema_cursor *)cur;
- switch( i ){
- case 0:
- sqlite3_result_value(ctx, sqlite3_column_value(pCur->pDbList, 1));
- break;
- case 1:
- sqlite3_result_value(ctx, sqlite3_column_value(pCur->pTableList, 0));
- break;
- default:
- sqlite3_result_value(ctx, sqlite3_column_value(pCur->pColumnList, i-2));
- break;
- }
- return SQLITE_OK;
-}
-
-/*
-** Retrieve the current rowid.
-*/
-static int schemaRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
- schema_cursor *pCur = (schema_cursor *)cur;
- *pRowid = pCur->rowid;
- return SQLITE_OK;
-}
-
-static int finalize(sqlite3_stmt **ppStmt){
- int rc = sqlite3_finalize(*ppStmt);
- *ppStmt = 0;
- return rc;
-}
-
-static int schemaEof(sqlite3_vtab_cursor *cur){
- schema_cursor *pCur = (schema_cursor *)cur;
- return (pCur->pDbList ? 0 : 1);
-}
-
-/*
-** Advance the cursor to the next row.
-*/
-static int schemaNext(sqlite3_vtab_cursor *cur){
- int rc = SQLITE_OK;
- schema_cursor *pCur = (schema_cursor *)cur;
- schema_vtab *pVtab = (schema_vtab *)(cur->pVtab);
- char *zSql = 0;
-
- while( !pCur->pColumnList || SQLITE_ROW!=sqlite3_step(pCur->pColumnList) ){
- if( SQLITE_OK!=(rc = finalize(&pCur->pColumnList)) ) goto next_exit;
-
- while( !pCur->pTableList || SQLITE_ROW!=sqlite3_step(pCur->pTableList) ){
- if( SQLITE_OK!=(rc = finalize(&pCur->pTableList)) ) goto next_exit;
-
- assert(pCur->pDbList);
- while( SQLITE_ROW!=sqlite3_step(pCur->pDbList) ){
- rc = finalize(&pCur->pDbList);
- goto next_exit;
- }
-
- /* Set zSql to the SQL to pull the list of tables from the
- ** sqlite_master (or sqlite_temp_master) table of the database
- ** identfied by the row pointed to by the SQL statement pCur->pDbList
- ** (iterating through a "PRAGMA database_list;" statement).
- */
- if( sqlite3_column_int(pCur->pDbList, 0)==1 ){
- zSql = sqlite3_mprintf(
- "SELECT name FROM sqlite_temp_master WHERE type=%Q",
- pVtab->pType->zObject
- );
- }else{
- sqlite3_stmt *pDbList = pCur->pDbList;
- zSql = sqlite3_mprintf(
- "SELECT name FROM %Q.sqlite_master WHERE type=%Q",
- sqlite3_column_text(pDbList, 1), pVtab->pType->zObject
- );
- }
- if( !zSql ){
- rc = SQLITE_NOMEM;
- goto next_exit;
- }
-
- rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pTableList, 0);
- sqlite3_free(zSql);
- if( rc!=SQLITE_OK ) goto next_exit;
- }
-
- /* Set zSql to the SQL to the table_info pragma for the table currently
- ** identified by the rows pointed to by statements pCur->pDbList and
- ** pCur->pTableList.
- */
- zSql = sqlite3_mprintf(pVtab->pType->zPragma,
- sqlite3_column_text(pCur->pDbList, 1),
- sqlite3_column_text(pCur->pTableList, 0)
- );
-
- if( !zSql ){
- rc = SQLITE_NOMEM;
- goto next_exit;
- }
- rc = sqlite3_prepare(pVtab->db, zSql, -1, &pCur->pColumnList, 0);
- sqlite3_free(zSql);
- if( rc!=SQLITE_OK ) goto next_exit;
- }
- pCur->rowid++;
-
-next_exit:
- /* TODO: Handle rc */
- return rc;
-}
-
-/*
-** Reset a schema table cursor.
-*/
-static int schemaFilter(
- sqlite3_vtab_cursor *pVtabCursor,
- int idxNum, const char *idxStr,
- int argc, sqlite3_value **argv
-){
- int rc;
- schema_vtab *pVtab = (schema_vtab *)(pVtabCursor->pVtab);
- schema_cursor *pCur = (schema_cursor *)pVtabCursor;
- pCur->rowid = 0;
- finalize(&pCur->pTableList);
- finalize(&pCur->pColumnList);
- finalize(&pCur->pDbList);
- rc = sqlite3_prepare(pVtab->db,"SELECT 0, 'main'", -1, &pCur->pDbList, 0);
- return (rc==SQLITE_OK ? schemaNext(pVtabCursor) : rc);
-}
-
-/*
-** Analyse the WHERE condition.
-*/
-static int schemaBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
- return SQLITE_OK;
-}
-
-/*
-** A virtual table module that merely echos method calls into TCL
-** variables.
-*/
-static sqlite3_module schemaModule = {
- 0, /* iVersion */
- schemaCreate,
- schemaCreate,
- schemaBestIndex,
- schemaDestroy,
- schemaDestroy,
- schemaOpen, /* xOpen - open a cursor */
- schemaClose, /* xClose - close a cursor */
- schemaFilter, /* xFilter - configure scan constraints */
- schemaNext, /* xNext - advance a cursor */
- schemaEof, /* xEof */
- schemaColumn, /* xColumn - read data */
- schemaRowid, /* xRowid - read data */
- 0, /* xUpdate */
- 0, /* xBegin */
- 0, /* xSync */
- 0, /* xCommit */
- 0, /* xRollback */
- 0, /* xFindMethod */
- 0, /* xRename */
-};
-
-/*
-** Extension load function.
-*/
-static int installSchemaModule(sqlite3 *db){
- sqlite3_create_module(db, "schema", &schemaModule, 0);
- return 0;
-}
-
-/**************************************************************************
-***************************************************************************
-** End of virtual table implementations.
-** Start of SQL user function implementations.
-*/
-
-/*
-** sj(zValue, zJoin)
-**
-** The following block contains the implementation of an aggregate
-** function that returns a string. Each time the function is stepped,
-** it appends data to an internal buffer. When the aggregate is finalized,
-** the contents of the buffer are returned.
-**
-** The first time the aggregate is stepped the buffer is set to a copy
-** of the first argument. The second time and subsequent times it is
-** stepped a copy of the second argument is appended to the buffer, then
-** a copy of the first.
-**
-** Example:
-**
-** INSERT INTO t1(a) VALUES('1');
-** INSERT INTO t1(a) VALUES('2');
-** INSERT INTO t1(a) VALUES('3');
-** SELECT sj(a, ', ') FROM t1;
-**
-** => "1, 2, 3"
-**
-*/
-struct StrBuffer {
- char *zBuf;
-};
-typedef struct StrBuffer StrBuffer;
-static void joinFinalize(sqlite3_context *context){
- StrBuffer *p;
- p = (StrBuffer *)sqlite3_aggregate_context(context, sizeof(StrBuffer));
- sqlite3_result_text(context, p->zBuf, -1, SQLITE_TRANSIENT);
- sqlite3_free(p->zBuf);
-}
-static void joinStep(
- sqlite3_context *context,
- int argc,
- sqlite3_value **argv
-){
- StrBuffer *p;
- p = (StrBuffer *)sqlite3_aggregate_context(context, sizeof(StrBuffer));
- if( p->zBuf==0 ){
- p->zBuf = sqlite3_mprintf("%s", sqlite3_value_text(argv[0]));
- }else{
- char *zTmp = p->zBuf;
- p->zBuf = sqlite3_mprintf("%s%s%s",
- zTmp, sqlite3_value_text(argv[1]), sqlite3_value_text(argv[0])
- );
- sqlite3_free(zTmp);
- }
-}
-
-/*
-** dq(zString)
-**
-** This scalar function accepts a single argument and interprets it as
-** a text value. The return value is the argument enclosed in double
-** quotes. If any double quote characters are present in the argument,
-** these are escaped.
-**
-** dq('the raven "Nevermore."') == '"the raven ""Nevermore."""'
-*/
-static void doublequote(
- sqlite3_context *context,
- int argc,
- sqlite3_value **argv
-){
- int ii;
- char *zOut;
- char *zCsr;
- const char *zIn = (const char *)sqlite3_value_text(argv[0]);
- int nIn = sqlite3_value_bytes(argv[0]);
-
- zOut = sqlite3_malloc(nIn*2+3);
- zCsr = zOut;
- *zCsr++ = '"';
- for(ii=0; ii<nIn; ii++){
- *zCsr++ = zIn[ii];
- if( zIn[ii]=='"' ){
- *zCsr++ = '"';
- }
- }
- *zCsr++ = '"';
- *zCsr++ = '\0';
-
- sqlite3_result_text(context, zOut, -1, SQLITE_TRANSIENT);
- sqlite3_free(zOut);
-}
-
-/*
-** multireplace(zString, zSearch1, zReplace1, ...)
-*/
-static void multireplace(
- sqlite3_context *context,
- int argc,
- sqlite3_value **argv
-){
- int i = 0;
- char *zOut = 0;
- int nOut = 0;
- int nMalloc = 0;
- const char *zIn = (const char *)sqlite3_value_text(argv[0]);
- int nIn = sqlite3_value_bytes(argv[0]);
-
- while( i<nIn ){
- const char *zCopy = &zIn[i];
- int nCopy = 1;
- int nReplace = 1;
- int j;
- for(j=1; j<(argc-1); j+=2){
- const char *z = (const char *)sqlite3_value_text(argv[j]);
- int n = sqlite3_value_bytes(argv[j]);
- if( n<=(nIn-i) && 0==strncmp(z, zCopy, n) ){
- zCopy = (const char *)sqlite3_value_text(argv[j+1]);
- nCopy = sqlite3_value_bytes(argv[j+1]);
- nReplace = n;
- break;
- }
- }
- if( (nOut+nCopy)>nMalloc ){
- nMalloc += (nMalloc + 16);
- zOut = (char *)sqlite3_realloc(zOut, nMalloc);
- }
- memcpy(&zOut[nOut], zCopy, nCopy);
- i += nReplace;
- nOut += nCopy;
- }
-
- sqlite3_result_text(context, zOut, nOut, SQLITE_TRANSIENT);
- sqlite3_free(zOut);
-}
-
-/**************************************************************************
-***************************************************************************
-** End of SQL user function implementations.
-** Start of application implementation.
-*/
-
-typedef struct Options Options;
-struct Options {
- char *zDb;
- int ignoreErrors;
- int noDrop;
-};
-
-/*
-** Print out a usage message for the command line and exit. This is
-** called from processCmdLine() if the program is invoked incorrectly.
-*/
-static int usage(char *zProgram){
- fprintf(stderr,
- "Usage: %s ?--ignore-errors? ?--no-drop? <database file>\n", zProgram
- );
- exit(-1);
-}
-
-static void processCmdLine(int nArg, char **azArg, Options *p){
- int i;
- assert( nArg>0 );
- if( nArg<2 ){
- usage(azArg[0]);
- }
- for(i=1; i<(nArg-1); i++){
- char *z = azArg[i];
- if( 0==strcmp(z, "--ignore-errors") ){
- p->ignoreErrors = 1;
- }
- else if( 0==strcmp(z, "--no-drop") ){
- p->noDrop = 1;
- }
- else usage(azArg[0]);
- }
- p->zDb = azArg[nArg-1];
-}
-
-/*
-** A callback for sqlite3_exec() that prints its first argument to
-** stdout followed by a newline.
-*/
-static int printString(void *p, int nArg, char **azArg, char **azCol){
- printf("%s\n", azArg[0]);
- return SQLITE_OK;
-}
-
-int detectSchemaProblem(
- sqlite3 *db, /* Database connection */
- const char *zMessage, /* English language error message */
- const char *zSql, /* SQL statement to run */
- int *pHasErrors /* Set *pHasErrors==1 if errors found */
-){
- sqlite3_stmt *pStmt;
- int rc;
- rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
- if( rc!=SQLITE_OK ){
- return rc;
- }
- while( SQLITE_ROW==sqlite3_step(pStmt) ){
- char *zDel;
- int iFk = sqlite3_column_int(pStmt, 0);
- const char *zTab = (const char *)sqlite3_column_text(pStmt, 1);
- fprintf(stderr, "Error in table %s: %s\n", zTab, zMessage);
- zDel = sqlite3_mprintf(
- "DELETE FROM temp.fkey WHERE from_tbl = %Q AND fkid = %d"
- , zTab, iFk
- );
- sqlite3_exec(db, zDel, 0, 0, 0);
- sqlite3_free(zDel);
- *pHasErrors = 1;
- }
- sqlite3_finalize(pStmt);
- return SQLITE_OK;
-}
-
-/*
-** Create and populate temporary table "fkey".
-*/
-static int populateTempTable(sqlite3 *db, char **pzErr, int *pHasErrors){
- int rc;
-
- rc = sqlite3_exec(db,
- "CREATE VIRTUAL TABLE temp.v_fkey USING schema(foreign_key_list);"
- "CREATE VIRTUAL TABLE temp.v_col USING schema(table_info);"
- "CREATE VIRTUAL TABLE temp.v_idxlist USING schema(index_list);"
- "CREATE VIRTUAL TABLE temp.v_idxinfo USING schema(index_info);"
-
- "CREATE TABLE temp.fkey AS "
- "SELECT from_tbl, to_tbl, fkid, from_col, to_col, on_update, on_delete "
- "FROM temp.v_fkey WHERE database = 'main';"
-
- , 0, 0, pzErr
- );
- if( rc!=SQLITE_OK ) return rc;
-
- rc = detectSchemaProblem(db, "foreign key columns do not exist",
- "SELECT fkid, from_tbl "
- "FROM temp.fkey "
- "WHERE to_col IS NOT NULL AND NOT EXISTS (SELECT 1 "
- "FROM temp.v_col WHERE tablename=to_tbl AND name==to_col"
- ")", pHasErrors
- );
- if( rc!=SQLITE_OK ) return rc;
-
- /* At this point the temp.fkey table is mostly populated. If any foreign
- ** keys were specified so that they implicitly refer to they primary
- ** key of the parent table, the "to_col" values of the temp.fkey rows
- ** are still set to NULL.
- **
- ** This is easily fixed for single column primary keys, but not for
- ** composites. With a composite primary key, there is no way to reliably
- ** query sqlite for the order in which the columns that make up the
- ** composite key were declared i.e. there is no way to tell if the
- ** schema actually contains "PRIMARY KEY(a, b)" or "PRIMARY KEY(b, a)".
- ** Therefore, this case is not handled. The following function call
- ** detects instances of this case.
- */
- rc = detectSchemaProblem(db, "implicit mapping to composite primary key",
- "SELECT fkid, from_tbl "
- "FROM temp.fkey "
- "WHERE to_col IS NULL "
- "GROUP BY fkid, from_tbl HAVING count(*) > 1", pHasErrors
- );
- if( rc!=SQLITE_OK ) return rc;
-
- /* Detect attempts to implicitly map to the primary key of a table
- ** that has no primary key column.
- */
- rc = detectSchemaProblem(db, "implicit mapping to non-existant primary key",
- "SELECT fkid, from_tbl "
- "FROM temp.fkey "
- "WHERE to_col IS NULL AND NOT EXISTS "
- "(SELECT 1 FROM temp.v_col WHERE pk AND tablename = temp.fkey.to_tbl)"
- , pHasErrors
- );
- if( rc!=SQLITE_OK ) return rc;
-
- /* Fix all the implicit primary key mappings in the temp.fkey table. */
- rc = sqlite3_exec(db,
- "UPDATE temp.fkey SET to_col = "
- "(SELECT name FROM temp.v_col WHERE pk AND tablename=temp.fkey.to_tbl)"
- " WHERE to_col IS NULL;"
- , 0, 0, pzErr
- );
- if( rc!=SQLITE_OK ) return rc;
-
- /* Now check that all all parent keys are either primary keys or
- ** subject to a unique constraint.
- */
- rc = sqlite3_exec(db,
- "CREATE TABLE temp.idx2 AS SELECT "
- "il.tablename AS tablename,"
- "ii.indexname AS indexname,"
- "ii.name AS col "
- "FROM temp.v_idxlist AS il, temp.v_idxinfo AS ii "
- "WHERE il.isunique AND il.database='main' AND ii.indexname = il.name;"
- "INSERT INTO temp.idx2 "
- "SELECT tablename, 'pk', name FROM temp.v_col WHERE pk;"
-
- "CREATE TABLE temp.idx AS SELECT "
- "tablename, indexname, sj(dq(col),',') AS cols "
- "FROM (SELECT * FROM temp.idx2 ORDER BY col) "
- "GROUP BY tablename, indexname;"
-
- "CREATE TABLE temp.fkey2 AS SELECT "
- "fkid, from_tbl, to_tbl, sj(dq(to_col),',') AS cols "
- "FROM (SELECT * FROM temp.fkey ORDER BY to_col) "
- "GROUP BY fkid, from_tbl;"
- , 0, 0, pzErr
- );
- if( rc!=SQLITE_OK ) return rc;
- rc = detectSchemaProblem(db, "foreign key is not unique",
- "SELECT fkid, from_tbl "
- "FROM temp.fkey2 "
- "WHERE NOT EXISTS (SELECT 1 "
- "FROM temp.idx WHERE tablename=to_tbl AND fkey2.cols==idx.cols"
- ")", pHasErrors
- );
- if( rc!=SQLITE_OK ) return rc;
-
- return rc;
-}
-
-int main(int argc, char **argv){
- sqlite3 *db;
- Options opt = {0, 0, 0};
- int rc;
- int hasErrors = 0;
- char *zErr = 0;
- const int enc = SQLITE_UTF8;
-
- const char *zSql =
- "SELECT multireplace('"
-
- "-- Triggers for foreign key mapping:\n"
- "--\n"
- "-- /from_readable/ REFERENCES /to_readable/\n"
- "-- on delete /on_delete/\n"
- "-- on update /on_update/\n"
- "--\n"
-
- /* The "BEFORE INSERT ON <referencing>" trigger. This trigger's job is to
- ** throw an exception if the user tries to insert a row into the
- ** referencing table for which there is no corresponding row in
- ** the referenced table.
- */
- "CREATE TRIGGER /name/_insert_referencing BEFORE INSERT ON /tbl/ WHEN \n"
- " /key_notnull/ AND NOT EXISTS (SELECT 1 FROM /ref/ WHERE /cond1/)\n"
- "BEGIN\n"
- " SELECT RAISE(ABORT, ''constraint failed'');\n"
- "END;\n"
-
- /* The "BEFORE UPDATE ON <referencing>" trigger. This trigger's job
- ** is to throw an exception if the user tries to update a row in the
- ** referencing table causing it to correspond to no row in the
- ** referenced table.
- */
- "CREATE TRIGGER /name/_update_referencing BEFORE\n"
- " UPDATE OF /rkey_list/ ON /tbl/ WHEN \n"
- " /key_notnull/ AND \n"
- " NOT EXISTS (SELECT 1 FROM /ref/ WHERE /cond1/)\n"
- "BEGIN\n"
- " SELECT RAISE(ABORT, ''constraint failed'');\n"
- "END;\n"
-
-
- /* The "BEFORE DELETE ON <referenced>" trigger. This trigger's job
- ** is to detect when a row is deleted from the referenced table to
- ** which rows in the referencing table correspond. The action taken
- ** depends on the value of the 'ON DELETE' clause.
- */
- "CREATE TRIGGER /name/_delete_referenced BEFORE DELETE ON /ref/ WHEN\n"
- " EXISTS (SELECT 1 FROM /tbl/ WHERE /cond2/)\n"
- "BEGIN\n"
- " /delete_action/\n"
- "END;\n"
-
- /* The "BEFORE DELETE ON <referenced>" trigger. This trigger's job
- ** is to detect when the key columns of a row in the referenced table
- ** to which one or more rows in the referencing table correspond are
- ** updated. The action taken depends on the value of the 'ON UPDATE'
- ** clause.
- */
- "CREATE TRIGGER /name/_update_referenced AFTER\n"
- " UPDATE OF /fkey_list/ ON /ref/ WHEN \n"
- " EXISTS (SELECT 1 FROM /tbl/ WHERE /cond2/)\n"
- "BEGIN\n"
- " /update_action/\n"
- "END;\n"
- "'"
-
- /* These are used in the SQL comment written above each set of triggers */
- ", '/from_readable/', from_tbl || '(' || sj(from_col, ', ') || ')'"
- ", '/to_readable/', to_tbl || '(' || sj(to_col, ', ') || ')'"
- ", '/on_delete/', on_delete"
- ", '/on_update/', on_update"
-
- ", '/name/', 'genfkey' || min(rowid)"
- ", '/tbl/', dq(from_tbl)"
- ", '/ref/', dq(to_tbl)"
- ", '/key_notnull/', sj('new.' || dq(from_col) || ' IS NOT NULL', ' AND ')"
-
- ", '/fkey_list/', sj(to_col, ', ')"
- ", '/rkey_list/', sj(from_col, ', ')"
-
- ", '/cond1/', sj(multireplace('new./from/ == /to/'"
- ", '/from/', dq(from_col)"
- ", '/to/', dq(to_col)"
- "), ' AND ')"
- ", '/cond2/', sj(multireplace('old./to/ == /from/'"
- ", '/from/', dq(from_col)"
- ", '/to/', dq(to_col)"
- "), ' AND ')"
-
- ", '/update_action/', CASE on_update "
- "WHEN 'SET NULL' THEN "
- "multireplace('UPDATE /tbl/ SET /setlist/ WHERE /where/;' "
- ", '/setlist/', sj(from_col||' = NULL',', ')"
- ", '/tbl/', dq(from_tbl)"
- ", '/where/', sj(from_col||' = old.'||dq(to_col),' AND ')"
- ")"
- "WHEN 'CASCADE' THEN "
- "multireplace('UPDATE /tbl/ SET /setlist/ WHERE /where/;' "
- ", '/setlist/', sj(dq(from_col)||' = new.'||dq(to_col),', ')"
- ", '/tbl/', dq(from_tbl)"
- ", '/where/', sj(dq(from_col)||' = old.'||dq(to_col),' AND ')"
- ")"
- "ELSE "
- " 'SELECT RAISE(ABORT, ''constraint failed'');'"
- "END "
-
- ", '/delete_action/', CASE on_delete "
- "WHEN 'SET NULL' THEN "
- "multireplace('UPDATE /tbl/ SET /setlist/ WHERE /where/;' "
- ", '/setlist/', sj(from_col||' = NULL',', ')"
- ", '/tbl/', dq(from_tbl)"
- ", '/where/', sj(from_col||' = old.'||dq(to_col),' AND ')"
- ")"
- "WHEN 'CASCADE' THEN "
- "multireplace('DELETE FROM /tbl/ WHERE /where/;' "
- ", '/tbl/', dq(from_tbl)"
- ", '/where/', sj(dq(from_col)||' = old.'||dq(to_col),' AND ')"
- ")"
- "ELSE "
- " 'SELECT RAISE(ABORT, ''constraint failed'');'"
- "END "
-
- ") FROM temp.fkey "
- "GROUP BY from_tbl, fkid"
- ;
-
- processCmdLine(argc, argv, &opt);
-
- /* Open the database handle. */
- rc = sqlite3_open_v2(opt.zDb, &db, SQLITE_OPEN_READONLY, 0);
- if( rc!=SQLITE_OK ){
- fprintf(stderr, "Error opening database file: %s\n", sqlite3_errmsg(db));
- return -1;
- }
-
- /* Create the special scalar and aggregate functions used by this program. */
- sqlite3_create_function(db, "dq", 1, enc, 0, doublequote, 0, 0);
- sqlite3_create_function(db, "multireplace", -1, enc, db, multireplace, 0, 0);
- sqlite3_create_function(db, "sj", 2, enc, 0, 0, joinStep, joinFinalize);
-
- /* Install the "schema" virtual table module */
- installSchemaModule(db);
-
- /* Create and populate a temp table with the information required to
- ** build the foreign key triggers. See function populateTempTable()
- ** for details.
- */
- rc = populateTempTable(db, &zErr, &hasErrors);
- if( rc!=SQLITE_OK ){
- fprintf(stderr, "Error reading database: %s\n", zErr);
- return -1;
- }
- if( hasErrors && opt.ignoreErrors==0 ){
- return -1;
- }
-
- printf("BEGIN;\n");
-
- /* Unless the --no-drop option was specified, generate DROP TRIGGER
- ** statements to drop any triggers in the database generated by a
- ** previous run of this program.
- */
- if( opt.noDrop==0 ){
- rc = sqlite3_exec(db,
- "SELECT 'DROP TRIGGER' || ' ' || dq(name) || ';'"
- "FROM sqlite_master "
- "WHERE type='trigger' AND substr(name, 0, 7) == 'genfkey'"
- , printString, 0, 0
- );
- if( rc!=SQLITE_OK ){
- const char *zMsg = sqlite3_errmsg(db);
- fprintf(stderr, "Generating drop triggers failed: %s\n", zMsg);
- return -1;
- }
- }
-
- /* Run the main query to create the trigger definitions. */
- rc = sqlite3_exec(db, zSql, printString, 0, 0);
- if( rc!=SQLITE_OK ){
- fprintf(stderr, "Generating triggers failed: %s\n", sqlite3_errmsg(db));
- return -1;
- }
-
- printf("COMMIT;\n");
- return 0;
-}
-
projects / thirdparty / sqlite.git / commitdiff
