// Checks whether or not a patch has been applied on database
func hasPatchApplied(dbConfig *patchsql.DatabaseConfig, patchConfig *PatchConfig) (result bool, err error) {
result = false
err = dbConfig.Execute(
func(db *dbsql.DB) (err error) {
var successRow = -1
if err = db.QueryRow(
`
SELECT COUNT(dcl_id)
FROM sysdb_change_log
WHERE dcl_named_id = ?
AND dcl_result = 2
ORDER BY dcl_time_update DESC
LIMIT 1
`,
patchConfig.Id,
).Scan(&successRow); err != nil {
return
}
result = successRow == 1
return
},
)
return
}
// Checks whether or not a patch has been applied on database
func hasPatchApplied(dbConfig *patchsql.DatabaseConfig, patchConfig *PatchConfig) (result bool, err error) {
result = false
err = dbConfig.Execute(
func(db *dbsql.DB) (err error) {
var successRow = -1
/**
* Since MySQL would gives you total number of COUNT(*)
* even if you use limit express,
* we just check the counting of success patching >= 1
*/
if err = db.QueryRow(
`
SELECT COUNT(*)
FROM sysdb_change_log
WHERE dcl_named_id = ?
AND dcl_result = 2
ORDER BY dcl_time_update DESC
`,
patchConfig.Id,
).Scan(&successRow); err != nil {
return
}
result = successRow >= 1
return
},
)
return
}
// 1. Add log to database
// 2. Applies patch to database
// 3. Update result patching on log in database
func applyPatch(
dbConfig *patchsql.DatabaseConfig,
patchConfig *PatchConfig,
scripts []string,
) (err error) {
var patchContent = patchResult{
patchConfig: patchConfig,
}
/**
* Add log to dtaabase
*/
if err = dbConfig.Execute(newChangeLogFunc(&patchContent)); err != nil {
return
}
// :~)
/**
* Applies scripts to database
*/
for _, script := range scripts {
log.Printf("Applying script:\n%v\n", script)
if err = dbConfig.Execute(
func(db *dbsql.DB) (err error) {
_, err = db.Exec(script)
return
},
); err != nil {
/**
* Logs the failed result to database
*/
patchContent.result = failed
patchContent.message = fmt.Sprintf("Error: [%v]\nScript:\n%v\n", err, script)
if logErr := dbConfig.Execute(updateChangeLogFunc(&patchContent)); logErr != nil {
panic(fmt.Errorf("Cannot log failed patching: [%v]. Error: %f.\nScript:\n%v\n", patchConfig.Id, err, script))
}
// :~)
return
}
}
// :~)
/**
* Update result patching on log in database
*/
patchContent.result = success
if err = dbConfig.Execute(updateChangeLogFunc(&patchContent)); err != nil {
return
}
// :~)
return
}
// Executes the patches in change log
func ExecutePatches(changeLogConfig *ChangeLogConfig) (err error) {
/**
* Loads configuration of patches
*/
var loadedPatches []PatchConfig
if loadedPatches, err = LoadChangeLogFromFile(changeLogConfig.ChangeLog); err != nil {
return
}
// :~)
/**
* Connect to database
*/
var dbConfig *patchsql.DatabaseConfig
if dbConfig, err = patchsql.NewDatabaseConfig(
changeLogConfig.DriverName,
changeLogConfig.Dsn,
); err != nil {
return
}
defer dbConfig.Close()
// :~)
/**
* Checking the schema for change log
*/
if err = dbConfig.Execute(checkChangeLogSchema); err != nil {
return
}
// :~)
/**
* Iterates each patch and applies it to database
*/
var numberOfApplied = 0
for _, p := range loadedPatches {
/**
* Checks if the patch has been applied
*/
if patchApplied, _ := hasPatchApplied(dbConfig, &p); patchApplied {
continue
}
// :~)
log.Printf("Applying patch: [%v](%v)...", p.Id, p.Filename)
var scripts []string
/**
* Loads scripts from file
*/
if scripts, err = p.loadScripts(changeLogConfig.PatchFileBase, changeLogConfig.Delimiter); err != nil {
return fmt.Errorf("Load script file[%v/%v] error: %v", changeLogConfig.PatchFileBase, p.Filename, err)
}
// :~)
/**
* Applies patch to database
*/
if err = applyPatch(dbConfig, &p, scripts); err != nil {
var patchErr = fmt.Errorf("Patch [%v](%v) has error: %v", p.Id, p.Filename, err)
log.Println(patchErr)
return patchErr
}
// :~)
numberOfApplied++
log.Printf("Applying patch success. [%v](%v).", p.Id, p.Filename)
}
// :~)
log.Printf("Number of applied patches: %v", numberOfApplied)
return
}