dump.c

这个是内存数据库的客户端

		pkeys[nkeys - 1] = c_pcolumn;
		fkeys[nkeys - 1] = c_fcolumn;
		while ((cnt = mapi_fetch_row(hdl)) != 0 && strcmp(mapi_fetch_field(hdl, 3), "0") != 0) {
			nkeys++;
			pkeys = realloc(pkeys, nkeys * sizeof(*pkeys));
			fkeys = realloc(fkeys, nkeys * sizeof(*fkeys));
			pkeys[nkeys - 1] = mapi_fetch_field(hdl, 1);
			fkeys[nkeys - 1] = mapi_fetch_field(hdl, 2);
		}
		fprintf(toConsole, ",\n\t");
		if (c_fkname) {
			fprintf(toConsole, "CONSTRAINT ");
			quoted_print(toConsole, c_fkname);
			putc(' ', toConsole);
		}
		fprintf(toConsole, "FOREIGN KEY (");
		for (i = 0; i < nkeys; i++) {
			if (i > 0)
				fprintf(toConsole, ", ");
			quoted_print(toConsole, fkeys[i]);
		}
		fprintf(toConsole, ") REFERENCES ");
		quoted_print(toConsole, c_name);
		fprintf(toConsole, " (");
		for (i = 0; i < nkeys; i++) {
			if (i > 0)
				fprintf(toConsole, ", ");
			quoted_print(toConsole, pkeys[i]);
		}
		fprintf(toConsole, ")");
		free(fkeys);
		free(pkeys);
	}
	if (mapi_error(mid)) {
		mapi_explain_query(hdl, stderr);
		mapi_close_handle(hdl);
		free(query);
		return 1;
	}
	mapi_close_handle(hdl);

	fprintf(toConsole, "\n");

	fprintf(toConsole, ");\n");

	snprintf(query, maxquerylen,
		 "SELECT \"i\".\"name\", "		/* 0 */
			"\"k\".\"name\", "		/* 1 */
			"\"kc\".\"nr\", "		/* 2 */
			"\"c\".\"name\" "		/* 3 */
		 "FROM \"idxs\" AS \"i\" LEFT JOIN \"keys\" AS \"k\" "
				"ON \"i\".\"name\" = \"k\".\"name\", "
		      "\"keycolumns\" AS \"kc\", "
		      "\"columns\" AS \"c\", "
		      "\"tables\" AS \"t\" "
		 "WHERE \"i\".\"table_id\" = \"t\".\"id\" AND "
		       "\"i\".\"id\" = \"kc\".\"id\" AND "
		       "\"t\".\"id\" = \"c\".\"table_id\" AND "
		       "\"kc\".\"column\" = \"c\".\"name\" AND "
		       "(\"k\".\"type\" IS NULL OR \"k\".\"type\" = 1) AND "
		       "\"t\".\"name\" = '%s' "
		 "ORDER BY \"i\".\"name\", \"kc\".\"nr\"", tname);
	if ((hdl = mapi_query(mid, query)) == NULL || mapi_error(mid)) {
		if (hdl) {
			mapi_explain_query(hdl, stderr);
			mapi_close_handle(hdl);
		} else
			mapi_explain(mid, stderr);
		free(query);
		return 1;
	}
	cnt = 0;
	while (mapi_fetch_row(hdl) != 0) {
		char *i_name = mapi_fetch_field(hdl, 0);
		char *k_name = mapi_fetch_field(hdl, 1);
		char *kc_nr = mapi_fetch_field(hdl, 2);
		char *c_name = mapi_fetch_field(hdl, 3);

		if (mapi_error(mid)) {
			mapi_explain_query(hdl, stderr);
			mapi_close_handle(hdl);
			free(query);
			return 1;
		}
		if (k_name != NULL) {
			/* unique key, already handled */
			continue;
		}

		if (strcmp(kc_nr, "0") == 0) {
			if (cnt)
				fprintf(toConsole, ");\n");
			fprintf(toConsole, "CREATE INDEX ");
			quoted_print(toConsole, i_name);
			fprintf(toConsole, " ON ");
			quoted_print(toConsole, tname);
			fprintf(toConsole, " (");
			cnt = 1;
		} else
			fprintf(toConsole, ", ");
		quoted_print(toConsole, c_name);
	}
	if (cnt)
		fprintf(toConsole, ");\n");
	if (mapi_error(mid)) {
		mapi_explain_query(hdl, stderr);
		mapi_close_handle(hdl);
		free(query);
		return 1;
	}
	mapi_close_handle(hdl);

	snprintf(query, maxquerylen, "SELECT count(*) FROM \"%s\"", tname);
	if ((hdl = mapi_query(mid, query)) == NULL || mapi_error(mid)) {
		if (hdl) {
			mapi_explain_query(hdl, stderr);
			mapi_close_handle(hdl);
		} else
			mapi_explain(mid, stderr);
		free(query);
		return 1;
	}
	if (mapi_fetch_row(hdl)) {
		char *cntfld = mapi_fetch_field(hdl, 0);

		fprintf(toConsole, "COPY %s RECORDS INTO ", cntfld);
		quoted_print(toConsole, tname);
		fprintf(toConsole, " FROM stdin USING DELIMITERS '\\t';\n");
	}
	mapi_close_handle(hdl);

	snprintf(query, maxquerylen, "SELECT * FROM \"%s\"", tname);
	if ((hdl = mapi_query(mid, query)) == NULL || mapi_error(mid)) {
		if (hdl) {
			mapi_explain_query(hdl, stderr);
			mapi_close_handle(hdl);
		} else
			mapi_explain(mid, stderr);
		free(query);
		return 1;
	}

	cnt = mapi_get_field_count(hdl);
	string = malloc(sizeof(int) * cnt);
	for (i = 0; i < cnt; i++) {
		string[i] = 0;
		if (strcmp(mapi_get_type(hdl, i), "char") == 0 || strcmp(mapi_get_type(hdl, i), "varchar") == 0) {
			string[i] = 1;
		}
	}
	while (mapi_fetch_row(hdl)) {
		char *s;

		for (i = 0; i < cnt; i++) {
			s = mapi_fetch_field(hdl, i);
			if (s == NULL)
				fputs("NULL", toConsole);
			else if (string[i]) {
				/* write double-quoted string with
				   certain characters escaped */
				quoted_print(toConsole, s);
			} else
				fputs(s, toConsole);
			if (i < cnt - 1)
				putc('\t', toConsole);
			else
				putc('\n', toConsole);
		}
	}
	free(string);
	if (mapi_error(mid)) {
		mapi_explain_query(hdl, stderr);
		mapi_close_handle(hdl);
		free(query);
		return 1;
	}
	mapi_close_handle(hdl);
	free(query);
	return 0;
}

int
dump_tables(Mapi mid, FILE *toConsole)
{
	const char *start = "START TRANSACTION";
	const char *end = "COMMIT";
	const char *sequences1 = "SELECT \"name\" FROM \"sequences\"";
	const char *sequences2 = "SELECT \"name\",get_value_for(\"name\"),\"minvalue\",\"maxvalue\",\"increment\",\"cycle\" FROM \"sequences\"";
	const char *tables = "SELECT \"name\" FROM \"_tables\" WHERE "
		"\"type\" = 0 AND \"system\" = FALSE";
	const char *views = "SELECT \"name\",\"query\" FROM \"_tables\" WHERE "
		"\"type\" = 1 AND \"system\" = FALSE";
	const char *functions = "SELECT \"func\" FROM \"functions\" WHERE "
		"\"sql\" = TRUE";
	MapiHdl hdl;
	int rc = 0;

	/* start a transaction for the dump */
	fprintf(toConsole, "START TRANSACTION;\n");

	if ((hdl = mapi_query(mid, start)) == NULL || mapi_error(mid)) {
		if (hdl) {
			mapi_explain_query(hdl, stderr);
			mapi_close_handle(hdl);
		} else
			mapi_explain(mid, stderr);
		return 1;
	}
	mapi_close_handle(hdl);

	/* dump sequences, part 1 */
	if ((hdl = mapi_query(mid, sequences1)) == NULL || mapi_error(mid)) {
		if (hdl) {
			mapi_explain_query(hdl, stderr);
			mapi_close_handle(hdl);
		} else
			mapi_explain(mid, stderr);
		return 1;
	}

	while (mapi_fetch_row(hdl) != 0) {
		char *name = mapi_fetch_field(hdl, 0);

		fprintf(toConsole, "CREATE SEQUENCE \"%s\" AS INTEGER;\n", name);
	}
	if (mapi_error(mid)) {
		mapi_explain_query(hdl, stderr);
		mapi_close_handle(hdl);
		return 1;
	}
	mapi_close_handle(hdl);

	/* dump tables */
	if ((hdl = mapi_query(mid, tables)) == NULL || mapi_error(mid)) {
		if (hdl) {
			mapi_explain_query(hdl, stderr);
			mapi_close_handle(hdl);
		} else
			mapi_explain(mid, stderr);
		return 1;
	}

	while (mapi_fetch_row(hdl) != 0) {
		char *tname = mapi_fetch_field(hdl, 0);

		rc += dump_table(mid, tname, toConsole);
	}
	if (mapi_error(mid)) {
		mapi_explain_query(hdl, stderr);
		mapi_close_handle(hdl);
		return 1;
	}
	mapi_close_handle(hdl);

	/* dump sequences, part 2 */
	if ((hdl = mapi_query(mid, sequences2)) == NULL || mapi_error(mid)) {
		if (hdl) {
			mapi_explain_query(hdl, stderr);
			mapi_close_handle(hdl);
		} else
			mapi_explain(mid, stderr);
		return 1;
	}

	while (mapi_fetch_row(hdl) != 0) {
		char *name = mapi_fetch_field(hdl, 0);
		char *restart = mapi_fetch_field(hdl, 1);
		char *minvalue = mapi_fetch_field(hdl, 2);
		char *maxvalue = mapi_fetch_field(hdl, 3);
		char *increment = mapi_fetch_field(hdl, 4);
		char *cycle = mapi_fetch_field(hdl, 5);

		fprintf(toConsole, "ALTER SEQUENCE \"%s\" RESTART WITH %s", name, restart);
		if (strcmp(increment, "1") != 0)
			fprintf(toConsole, " INCREMENT BY %s", increment);
		if (strcmp(minvalue, "0") != 0)
			fprintf(toConsole, " MINVALUE %s", minvalue);
		if (strcmp(maxvalue, "0") != 0)
			fprintf(toConsole, " MAXVALUE %s", maxvalue);
		fprintf(toConsole, " %sCYCLE;\n", strcmp(cycle, "true") == 0 ? "" : "NO ");
	}
	if (mapi_error(mid)) {
		mapi_explain_query(hdl, stderr);
		mapi_close_handle(hdl);
		return 1;
	}
	mapi_close_handle(hdl);

	/* dump views */
	if ((hdl = mapi_query(mid, views)) == NULL || mapi_error(mid)) {
		if (hdl) {
			mapi_explain_query(hdl, stderr);
			mapi_close_handle(hdl);
		} else
			mapi_explain(mid, stderr);
		return 1;
	}
	while (mapi_fetch_row(hdl) != 0) {
		char *vname = mapi_fetch_field(hdl, 0);
		char *query = mapi_fetch_field(hdl, 1);

		fprintf(toConsole, "CREATE VIEW ");
		quoted_print(toConsole, vname);
		fprintf(toConsole, " AS %s\n", query);
	}
	if (mapi_error(mid)) {
		mapi_explain_query(hdl, stderr);
		mapi_close_handle(hdl);
		return 1;
	}
	mapi_close_handle(hdl);

	/* dump functions */
	if ((hdl = mapi_query(mid, functions)) == NULL || mapi_error(mid)) {
		if (hdl) {
			mapi_explain_query(hdl, stderr);
			mapi_close_handle(hdl);
		} else
			mapi_explain(mid, stderr);
		return 1;
	}
	while (mapi_fetch_row(hdl) != 0) {
		char *query = mapi_fetch_field(hdl, 0);

		fprintf(toConsole, "%s\n", query);
	}
	if (mapi_error(mid)) {
		mapi_explain_query(hdl, stderr);
		mapi_close_handle(hdl);
		return 1;
	}
	mapi_close_handle(hdl);

	if ((hdl = mapi_query(mid, end)) == NULL || mapi_error(mid)) {
		if (hdl) {
			mapi_explain_query(hdl, stderr);
			mapi_close_handle(hdl);
		} else
			mapi_explain(mid, stderr);
		return 1;
	}
	mapi_close_handle(hdl);

	/* finally commit the whole transaction */
	fprintf(toConsole, "COMMIT;\n");

	return rc;
}