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/*
* (C) Copyright 1996-2012 ECMWF.
*
* This software is licensed under the terms of the Apache Licence Version 2.0
* which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
* In applying this licence, ECMWF does not waive the privileges and immunities
* granted to it by virtue of its status as an intergovernmental organisation nor
* does it submit to any jurisdiction.
*/
/// \file examples.cc
///
/// This file contains examples of usage of public APIs.
///
/// @author Piotr Kuchta, ECMWF, July 2016
#include "odb_api/odbql.h"
// We need to include stdio.h for the fprintf declaration
#include "stdio.h"
#define checkRC(return_code, message, db) { \
if (return_code != ODBQL_OK) { \
fprintf(stderr, "%s: %s\n", message, odbql_errmsg(db)); \
odbql_close(db); \
return 1; \
} \
}
int odbql_example_insert_data()
{
odbql *db;
odbql_stmt *stmt;
int i;
int rc = odbql_open("", &db);
checkRC(rc, "Cannot open database", db);
rc = odbql_prepare_v2(db, "CREATE TYPE bf AS (f1 bit1, f2 bit2);\n"
"CREATE TABLE foo AS"
" (x INTEGER, y REAL, v STRING, status bf)"
" ON 'new_api_c_example.odb';",
-1,
&stmt,
0);
checkRC(rc, "Failed to prepare DDL statements", db);
rc = odbql_prepare_v2(db,
"INSERT INTO foo (x,y,v,status) VALUES (?,?,?,?);",
-1,
&stmt,
0);
checkRC(rc, "Failed to prepare INSERT statement", db);
// Populate first row with NULLs
for (i = 0; i < 4; ++i)
odbql_bind_null(stmt, i);
rc = odbql_step(stmt);
// Few more rows with some non-NULL values
for (i = 0 ; i < 4; ++i)
{
rc = odbql_bind_int(stmt, 0, 1 * i);
checkRC(rc, "Failed to bind int value", db);
rc = odbql_bind_double(stmt, 1, 0.1 * i);
checkRC(rc, "Failed to bind double value", db);
rc = odbql_bind_text(stmt, 2, i%2 ? "hello" : "HELLO", 5 /* strlen("hello") */, ODBQL_STATIC);
checkRC(rc, "Failed to bind string", db);
rc = odbql_bind_int(stmt, 3, 3 * i);
checkRC(rc, "Failed to bind bitfield value", db);
rc = odbql_step(stmt);
//checkRC(rc, "Failed to step and write row", db);
}
rc = odbql_finalize(stmt);
checkRC(rc, "odbql_finalize failed", db);
rc = odbql_close(db);
checkRC(rc, "odbql_close failed", db);
return 0;
}
int odbql_example_select_data_read_results()
{
odbql *db;
odbql_stmt *res;
int i, rc, column, number_of_columns;
long long number_of_rows = 0, number_of_rows_in_current_dataset = 0;
rc = odbql_open("new_api_c_example.odb", &db);
//" ON 'mars://RETRIEVE,CLASS=OD,TYPE=MFB,STREAM=OPER,EXPVER=0001,DATE=20160720,TIME=1200,DATABASE=marsod';", &db);
checkRC(rc, "Cannot open file", db);
//rc = odbql_prepare_v2(db, "SELECT x,y,v,status,status.* FROM foo;", -1, &res, 0);
rc = odbql_prepare_v2(db, "SELECT * FROM 'new_api_c_example.odb';", -1, &res, 0);
checkRC(rc, "Failed to prepare statement", db);
// Print rows of data.
while((rc = odbql_step(res)) != ODBQL_DONE)
{
if (number_of_rows == 0 || rc == ODBQL_METADATA_CHANGED)
{
number_of_columns = odbql_column_count(res);
if (number_of_rows_in_current_dataset)
printf("Number of rows: %d\n", number_of_rows_in_current_dataset);
/*
// Print CSV header. Each field is a colon separated pair of column name and type.
printf("\nNew dataset. Number of columns: %d\n", number_of_columns);
for (i = 0; i < number_of_columns; ++i)
printf("%s:%d%s", odbql_column_name(res, i),
odbql_column_type(res, i),
((i < number_of_columns - 1) ? "," : ""));
printf("\n");
*/
number_of_rows_in_current_dataset = 0;
}
if (rc == ODBQL_ROW)
{
column = 0;
/*
for (; column < number_of_columns; ++column)
{
printf("%s%s", odbql_column_value(res, column)
? odbql_column_text(res, column)
: (unsigned char *) "NULL",
((column < number_of_columns - 1) ? "," : ""));
}
*/
if (number_of_rows == 0)
{
for (i = 0; i < number_of_columns; ++i)
if (odbql_column_value(res, i)) return 100; // first row should be all NULLL
}
else
{
// Check first column
odbql_value* pv = odbql_column_value(res, 0);
if ( pv == 0 )
{
fprintf (stderr, "\nUnexpected NULL in column %ld of row %ld\n", 0L, number_of_rows);
return 101;
}
int iv = odbql_value_int(pv);
if ( iv != number_of_rows - 1)
{
fprintf (stderr, "\nUnexpected value in column %ld of row %ld\n", 0L, number_of_rows);
return 102;
}
// Check last column (bitfield)
// We have a NULL on the first column (set with odbql_bind_null)
// but also on the second line, because 0 in a bitfield column means NULL
// (ECMWF convention since ODB-1)
if (number_of_rows > 1)
{
pv = odbql_column_value(res, 3);
if ( pv == 0 )
{
fprintf (stderr, "\nUnexpected NULL in column %ld of row %ld\n", 3L, number_of_rows);
return 103;
}
iv = odbql_value_int(pv);
if ( iv != 3 * (number_of_rows - 1))
{
fprintf (stderr, "\nUnexpected value in column %ld of row %ld\n", 3L, number_of_rows);
return 104;
}
}
}
printf("\n");
}
++ number_of_rows;
++ number_of_rows_in_current_dataset;
}
if (number_of_rows_in_current_dataset)
printf("Number of rows: %d\n", number_of_rows_in_current_dataset);
printf("\nProcessed %ld rows.\n", number_of_rows);
return 0;
}
int odbql_example_execute_embedded_ecml()
{
odbql *db;
odbql_stmt *res;
int rc;
rc = odbql_open("new_api_c_example.odb", &db);
checkRC(rc, "Cannot open database", db);
rc = odbql_prepare_v2(db, " { compare, left = new_api_c_example.odb, right = new_api_c_example.odb }; ", -1, &res, 0);
checkRC(rc, "Failed to prepare embedded statement", db);
// Print rows of data.
while((rc = odbql_step(res)) != ODBQL_DONE)
{
printf("\n---\n");
}
rc = odbql_finalize(res);
checkRC(rc, "odbql_finalize failed", db);
rc = odbql_close(db);
checkRC(rc, "odbql_close failed", db);
return 0;
} |
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